... very interesting point of view on mitochondria and their role in the cell. I hope you will publish your observations soon ? I would like to read it :)

Dear Prof. Morelli, while collaborating with your collegue Isabella Panfoli in looking for ectopic respiratory chain enzymes in photoreceptor outer segments we are now also looking for in situ enzymatic reactions of complexes in the myelin sheets of the optic nerve - very interesting topic! we keep you updated!

Best regards

Richard Funk 

 I'm very interest to results of experiments on myelin in Dresda, by Richard Funk. Impressive is the recent work (doi: 10.1111/jnc.13142) of Olna Elroy-Stern group in Tel Aviv who confirm our vision, that mitochondria machinery is trasferred in myelin. To Magdalena Labieniec point out our recent papers that I send you by mail. Impressive is our results not even publisched: mitochondria make very few ATP. On the contrary Myelin produce ATP in a large amount. Our recent work (doi: 10.1007/s12035-015-9216-0) "supports the idea that ATP aerobically synthesized in myelin sheath could be transferred to the axoplasm through gap junctions" and "shed new light on the function of the sheath".

Dear Alessandro and Richard,

I was not really aware of this literature, very interesting concept indeed! How this might contribute to MS and ALS? Is there any hypothesis / idea?

Thanks,

Norbert

The link to MS is consolidate in the our research. We've a consistent lot of data on MS. For ALS we've only preliminary data. Briefly the MS is caracterized by a dramatic decrease of OXPHOS in myelin. We've attempt to publisched our data, but it was rejected because "it's not conform to tradition...". Moreover this is from our abstract just presented to a congress " ...By both biochemical and imaging techniques, we have observed that the presence and the functionality of the complete electron transport chain, normally present in myelin sheath, decrease drastically in the MS plaque. Moreover, this loss appears more serious in the active plaques respect the very early active plaques. These results could give a new input to the under standing of the correlation between the myelin loss and the axonal degeneration, clarifying the neuro-trophic role of myelin.

very interesting stuff Alessandro. Have you discussed those data with Dr. Peter Stys at the University of Calgary? He has a non conventional view of what MS might be and what you are showing goes to this direction.

thank you for papers prof. Morelli ... I follow this debate with a great interest. Unconventionally thinking in science is very necessary. Unfortunately, such 'revolutionary' data are difficult to publish, I know that :) Good luck.

Tank Norbert Weiss for the suggestion. I'll contact Prof. Peter Stys in Canada.

Very thank to Magdalene Labieniec for the encourarement to go on.

very interesting!

Considering "Warburg effect" Have you any try in cancer field?

If there are mt system in cytosol why the cancer cells mostly produce ATP through glycolysis? in other words have you challenge oxygen consumption till now?

Ali, You have hit the core of cancer energetic! Cancer cells need more energy than non trasformed cell and the belief that glycolysis supply (i.e. Warburg effect) is pathetic...because glycolisis is very limited in energetic supply! Our preliminary data indicate that in all the cell the bulk of respiration is extramitochondrial, which increase in cancer cells! Enlighten is the paper of Harrest & Berridge (doi:10.1016/j.bbabio.2006.11.018). Our preliminary data indicate a consistent role of hexose monophasphate shunt who link directly exose to triose phosphate by crucial enzyme Hexose-6-Phosphate-Dehydrogenase (more important tha well known G6PD), which bypass the first phase of glycolisis and the reduced equivalents produced is directly utilize by OXPHOS extramitocondrial, operative in endoplasmic reticulum. 30 % of ER proteins is mitochondrial (Stevens et al.- J. of Proteome Res 2008, 7, 1046–1054)! I think that ER is the true "lung" of the cells...

I am not very experienced in respiratory measurements of cancer cells but our studies revealed that some cancer lines, i.e. MCF-7 consume oxygen by mitochondria and produce quite a lot of ATP by OXPHOS. Now, we prepare these data to publication. I think that actually, there are a lot of papers indicating that cancer cells (at least some of their types) receive ATP not only by glycolysis but also by mitochondria activity.

We have seen (see attached paper) that C-6 glioma cells produce ATP by plama cells. Moreover the topic need more investigation.

Dear Professor Morelli,

many thanks for your question and apologies for delaying my answer, due to urgent issues. I already wrote you and your Colleagues that the research going on in your laboratory looks important not only for Neurobiology: the mitochondria themselves can deliver a limited amount of ATP to the cytosol; the oxidative phosphorylation machinery is exported from mitochondria into subcellular structures providing a more favorable ATP production; the application of this new paradigm on the function of myelin is impressive. The last paper you kindly sent me excluded that this involvement could be due to a contamination. A paper of mine published in 2001 under the title of “Knowledge of brain memory codification as a challenge for the Third Millennium” also worked around the idea that the wave of depolarization formed outside the axon membrane during the impulse conduction should require an extremely low amount of ATP energy. I strongly encourage you to continue such an original research.

Best regards

Prof. Pietro Volpe

Tank, Pietro Volpe. The new idea on bioenergetic was born by mine collegue Isabella Panfoli, who discovered that, in the disks of the rods, devoited of mitochondria, the ATP synthesis was happening to high rate.

After that we understood that very likely ever subcellar district need a local extramitocondrial -mitochondrial derivated- ATP production, and this idea was fed by impressive universal inconclusiveness of bionernegetic reserches, especially the neurobiology one. The application in neurobiology was accordingly, and the mysterious myelin was the second our target. We think that Chemiosmotic theory (basic paradigm in bioenergetic) need a update in deepness and in Genova in september 2016 it will take place a workshop an this pivotal topic. Same important scientist on this field have already expressed their interest.

This would definitely be a paradigm shift. Biochemists and oncologists understand that the increase anaerobic glycolysis is the major source of ATP production in cancerous cells. We believe that oxidative phosphorylation in the few mitochondria would not meet their need for ATP and the fact that they have increased normal glycolytic process gives an answer to how they survive that menace. To have a shift in this knowledge would be interesting, more especially if the mechanism of the process would be elucidated. Guessing through, it may be that the limited mitochondria are strong enough to produce this ATP or these electron carriers have alternative pathway that would bypass the complexes and F0F1ATPase of the mitochondria or maybe there are some organneles that could mimic mitochondria ATP production process in the same manner or different mode. Maybe!

It is to be put in serious doubt that "the increase anaerobic glycolysis is the major source of ATP production in cancerous cells". Experiments in our lab highlight that extramitocondrial respiration is very much more of that one own of the mitochondria wich as in normal as in trasformed cells doesn't synthesised the bulk of cellular ATP. Glycolisis was born in vegetables for go on the gluconeogenesis! Synthesis of ATP from glycolisis is absolutely inadeguate to supply the incresed domand of ATP of cancerous cells. Warburg effect borned around 1930...the times are ripe to accept other realities...see the attached paper...

Autophagy can be a major source of ATP?

Right? Specifically in case of mitochondrial damage.

Autophagy could help to provide substrates that could give ATP cellular combustion. In the brain, it seems likely that myelin meets autophagy with so much energy released as it is formed in high percentage of lipids. But the machinery that combines breathing substrates with oxygen to give ATP is, in the light of our experimentation, in extracellular districts. The fact remains that mitochondria alone can not produce all of the ATP that the cell needs.

Thank you very much for your nice comment. In fact there is growing concept called reverse Warburg effect; where oxidative stress -induced upregulation of glycolysis and autophagy in cancer associated fibroblats may fuel cancer epithelial cells with lactate and other nutrients resulting in increased ATP production.

Could both autophagy and glycolysis be a major source of ATP in cancer epithelial cells under hypoxic environments?

Too many issues are unclear, and I think that is why the metabolic alteration that characterizes tumors is unclear. For my philosophical training, the idea that putting together unclear issues can be made clear ... the obvious result is that the confusion increases! I think the first thing to clarify is anaerobic glycolysis if it can produce ATP. Many experimental and theoretical evidence tell us: it is not possible and the motivations can be explained if you ask me. Clarified this fixed point I think the tumors increase the anaerobic glycolysis, of course, but the first stage passes for the phosphate pentose shunt that produces NAPH reducing equivalents that discharge electrons towards extramitochondrial OXPHOS and thus produce the ATP of which the tumor cells have extreme need. But here it's all (almost) to do. We are publishing data in favor of the above. However, I attach a paper of many years ago that highlights the extramitochondrial OXPHOS in tumor cells.

Thank you very much for your comments and sending the paper.

Best wishes

Under chemo-osmotic theory any membrane with a pH gradient across it can drive ATP synthase. Conversely these can be run in reverse using ATP to create pH gradients and alter micro environments in vesicles. The electron transport chain is the oxygen dependent part.

for example.......

https://academic.oup.com/abbs/article/42/8/530/970/Mitochondrial-F1Fo-ATP-synthase-translocates-to

Thank you very much, Jason Iles!

You have highlighted a very controversial topic. From our work emerges that the chemiosmotic theory requires a profound revision. In short, it is not the membrane potential that synthesizes ATP at the ATP synthase, but there is a direct coupling with protonic movement across the membrane. We have pubklished it in 2013 (see paper attached). Protons can not accumulate on the membrane as it has unmistakably highlighted Wojciech Ball (see attached). On the plasma membrane, ATP synthase is able to synthesize external ATP. Polyphenols inhibit external ATP synthase and therefore, with a model we have elaborated, also internal ATP synthase and it is (problably)  for that mechanis why polyphenols are antitumour.

I insist on the need to resize the original Mithcell theory that has never been demonstrated in cells, but only in artificial membranes, with physical chemical forcing absolutely different from cellular processes. Here the talk is long ...

The autophagy plays certainly an important role indirect in ATP production, especially the lipophagy associated with NAFLD, but the problem I have is not what are the cell fuels that lead to the common ATP synthesis, but the cellular sites and molecular details on processes that produce ATPs. In other words, we are looking for the sites where oxidative phosphorylation occurs, and it is increasingly apparent that mitochondria alone can not synthesize all of the ATP that the cell needs. Among them, myelin appears increasingly interesting as a source of ATP for the neuron that has very little mitochondria. And it seems fascinating to locate a link that is likely to arise, between energy availability and possible cognitive functions.However, the same myelin, which has the highest lipid content in the body tissues, is easily exposed to lipophagy (we have preliminary data in this regard) and so, as you can see, I can give more openness to your interesting question by moving from the liver to the brain. I ask you: it can spread these ideas among its neurobiologist colleagues operating in Minnesota University?

We heve demonstrated and published (see paper" Extramitochondrial energy production in platelets" , Biol. Cell (2018) 110, 1–10 (attached) ) that platelets produce ingent quantity of ATP by extramitochondrial device, ie, OXPHOS full operative on endoplasmic reticulum. A set of data not yet published shows that a very active OXPHOS on ER is a widely diffused reality in various cell types.

After accumulating many laboratory findings, it is clear that the production of aerobic ATP is above all extramitochondrial, so that the classical chemiosmotic theory, which exclusively refers to the mitochondria, is not adequate. We have therefore published the article "Chemiosmotic coupling in Oxidative Phosphorylation: the history of a hard experimental effort hampered by the Heisenberg indeterminacy principle." PeerJ Preprints https://doi.org/10.7287/peerj.preprints.27241v1 - in which a new model of coupling between macromolecular complexes that move protons (for example the Respiratory Complex I) and the synthesizer of ATP (ie the ATP synthase) is formulated . The model predicts that the proton is never in free form and finds it plausible that the protonic currents operating exclusively in the membrane are active.

Open Biology recently published on 10 04 2019 the article:

"An update of the chemiosmotic theory as suggested by possible proton currents

inside the coupling membrane" http://dx.doi.org/10.1098/rsob.180221

Alessandro Maria Morelli, Silvia Ravera, Daniela Calzia and Isabella Panfoli

After more than half a century from its formulation, the chemiosmotic theory requires an update imposed by the detailed knowledge of the structures of the macromolecular complexes involved in the oxidative phosphorylation (OXPHOS) which was acquired in these recent two decades. The process, characterized by a great complexity, requires an integration between reactions occurring in the two distinct physical phases: the aqueous cytosol and the proteolipid membrane. The present knowledge indicates that the process needs two aqueous compartments separated by a membrane. Conversely, we propose a coupling strictly resident in the membrane between the generator of proton currents (i.e. respiratory complex) and the nanomolecular machine F1Fo-ATP synthase which synthesies ATP sustained by the proton current.

This update of the Chemiosmotic Theory suggest a new better theoretical interpretation of OXPHOS process that can function in cellular districts different from mitochondria such as the plasma membranes, the photoreceptors, the myelin sheath, the platelets.

In particular, the presence of active OXPHOS measured in myelin allowed us to formulate new hypotheses on the chemical-physical bases of myelined nerve conduction as reported in our previous article:

"The Myelin cannot change the basic mechanisms of axonal conduction" - Link: DOI: 10.7287/peerj.preprints.3409v1)

l be of interest and I am at disposal for any request for information and discussion.

Best regards,

Alessandro Morelli

Alessandro Morelli

It turns out the ER gets a big chunk of its ATP from mito-OxPHOS, if not all.

Please check out our paper at Article Mitochondria supply ATP to the ER through a mechanism antago...

Based on our experience, with measures repeatedly tried for years, it appears that the mitochondria produce very little ATP, certainly not enough to feed the whole cell, including ER. It is quite intuitive that having a double membrane system, the mitochondria are poorly suited to pass polyanions (such as ADP / ATP) through their membranes. The error can be understood considering that the first measurements carried out in the 1950s were made with prepractions containing a lot of ER and the first researchers measured the ATP produced by the ER, not by the mitochondria. With the improvement of the purification techniques it was soon realized that the mitochondria produced ATP below the sensitivity of the spectrophotomtric techniques and therefore it was proposed to measure it with the classical Clark oximeter methodology, accepting, pro bona fide, that the ATP product was equimolecular to the added ADP, but we have verified that this assumption is wrong. Today, with the luminometric technique, it is shown that the isolated mitochondria produce very little ATP of the order of 10 nmol / min / mg protein. Vice versa, the platelet ER produces 40-50 (!) Times higher ATP: see our article "Extramitochondrial energy production in platelets" Biol Cell. 2018 May; 110 (5): 97-108. We can proceed in comparing your data, which are very interesting, if you too accept this radical paradigm shift. We understand that it is not simple... But to encourage maximum dialogue between us, we attach our Insert published in the textbook "Biochemistry" Campbell-Farrell (Italian edition). We are extremely interested in hearing your opinion. I Attach also the list of our published article on extramitochondrial ATP synthesis.

As see you soon,

Alessandro Morelli

Now I attach the the list of our published articles on extramitochondrial ATP synthesis.

I guess the key question is to find this extra-mitochondrial ATP synthetase, and to reconstitute it in vitro in a high Ca2+ (~1mM) buffering system to mimic an ER environment. In our article, we have no doubt that ATP being synthesized is from OxPhos.

See Figure 3 at eLIFE:

Mitochondria supply ATP to the ER through a mechanism antago...

First of all I am happy that the discussion continues and I hope in your comments to what I am writing to you now. Certainly the reconstruction of the system is important to see the synthesis of ATP buffering from high Ca2 + in vitro but the heart of the matter is to accept that the mitochondria cannot supply the whole cell with ATP. In your experiments recently published on eLIFE you always use whole cells and therefore you have no tools to know who really synthesizes ATP. I found that the whole topic is affected by historical misliding. There is no doubt that the mitochondria possess the OXPHOS machinery but another argument is a real transfer of ATP from the mitochondria to other compartments such as the ER. Here it is not a question of fine reasoning but a duty-bound acceptance of the laboratory measures that tell us in a way that leaves no room for doubt that mitochondria cannot transfer this ATP for various reasons. List two:

1) Nucleotide Adenine Translocase (ANT) is not an antiport. It is a passive transporter for single ATP or ADP and it's supported by the concentration gradient. Now there is a multiplicity of reports that tell us that the concentration of cytosolic ATP is higher than the concentration of the ATP of the mitochondrial matrix (See “Visualization of ATP levels inside single living cells with fluorescence resonance energy transfer-based genetically encoded Indices” Imamura et al PNAS 2009; 106: 15651-6 quoted by yourself). An immense literature exists on ANT but I found only one paper (“Kinetic mechanism of exchanges catalysed by the adenine-nucleotide carrier“ Eur J Biochem. 1980 May; 106: 1-6.Duyckaerts C et al) which measures the kinetics of transport and confirms that ANT cannot take on the substantial transport of ATP / ADP. Furthermore the ATP / ADP transport speeds are very low and there is also a competitive inhibition which means that at equimolecular concentrations of ATP / ADP there is... no transport at all!

2) The transport of polyanions as ADP / ATP through any protein-phospholipid membrane is severely hampered by a barrier with dielectric constant lower than 80 which extends up to 10 nm from the membrane surface. This reality was highlighted by Mulkidjanian & Cherepanov ("Probing biological interfaces by tracing proton passage across them" Photochem Photobiol Sci. 2006 Jun; 5: 577-87.) Which we emphasize in a manuscript we are writing, which practice is the continuation of our first article published in Open Biology.

An obligatory question: "but if they do not produce ATP for the cell what is the role of mitochondria?" Several lines of evidence indicate that the very complicated OXPHOS machinery is assembled in the mitochondria, which is then probably exported by vesiculation to other membrane systems, primarily ER, where OXPHOS can take place unimpeded. The ER is thus able to synthesize the ATP itself through its own OXPHOS and this we have seen in our laboratory both in platelets and in many other situations that are the subject of manuscripts being written.

It is true that what we do nowadays is a continuation of what we know as "knowledge". It is possible that we all live in a matrix that all we learned from biochemistry textbooks is simply an illusion - how can we test it though?

For Dr. Imamura's probe and ERAT, I am positive that they work well. Good luck!

@@@@@@Dear Jing, It is absolutely not true that "all we learned from biochemistry textbooks is simply an illusion". A lot has happened and it is true but others are hypotheses that do not find proof and by dint of repeating them to us in the end we take them for true. Western thought owes much to Immanuel Kant who insisted that systematic doubt must be applied to what is transmitted to us by tradition. Today scientists are not inclined to develop a radical critique of what is transmitted to us by tradition and it is not even possible to do it otherwise the establishment of those in power denies funding to those who are not strictly canonical. Unfortunately in biology very often the strict laws of thermodynamics are not taken into account and it is thought that all reactions are possible. Let's recap: the mitochondria have the perfect "machine" for OXPHOS but they have too many limits, first of all two membrane systems. Among other things, if you want to tell you all the fantasies that have been published for the ANT that over the years there is only a paper that measures the actual transport ATP / ADP and finds that it is almost null (if you want I will tell you all this story. At a conference we talked about it at length with John Walker). With a colleague from Paris we are developing an interesting research that leads to consider the VDAC of the outer mitochondrial membrane as a mega channel through which blistered vesicles pass from the inner membrane and these vesicles would transfer the OXPHOS machinery to ER where it can express itself freely. Among other things, finally, one would find a convincing role for the VDAC of which everything and more was said ... Thanks for the good luck but we're lucky if we keep writing. Believe me the biochemical reality inside the cell and quite different from what is written on textbooks. However, together with Isabella we were able to write our "heresies" on a biochemistry textbook that was very positively received by the students (see attached) who have no more open mind and not yet oppressed by the so-called "knowledge". See you soon,          Sandro

PS: Imamura's FRET is splendid and they show what I say and you have to know that measurements two years ago with its probe showed the exceptional synthesis of ATP by myelin.

Alessandro Morelli

Your proposal is great.

Along the same line of thoughts, please check up Figure 3 in my paper, which demonstrates that Mitochondria are the ATP heroes in CHO system for ER.

and I lok forward to talking to you in person in the near future.

jing

Alessandro Morelli

Dear Alessandro,

i read the below a while ago, and would love to share it here -

Inseparable tandem: evolution chooses ATP and Ca2+ to control life, death and cellular signalling

Published:05 August 2016

https://doi.org/10.1098/rstb.2015.0419

Abstract

From the very dawn of biological evolution, ATP was selected as a multipurpose energy-storing molecule. Metabolism of ATP required intracellular free Ca2+ to be set at exceedingly low concentrations, which in turn provided the background for the role of Ca2+ as a universal signalling molecule. The early-eukaryote life forms also evolved functional compartmentalization and vesicle trafficking, which used Ca2+ as a universal signalling ion; similarly, Ca2+ is needed for regulation of ciliary and flagellar beat, amoeboid movement, intracellular transport, as well as of numerous metabolic processes. Thus, during evolution, exploitation of atmospheric oxygen and increasingly efficient ATP production via oxidative phosphorylation by bacterial endosymbionts were a first step for the emergence of complex eukaryotic cells. Simultaneously, Ca2+ started to be exploited for short-range signalling, despite restrictions by the preset phosphate-based energy metabolism, when both phosphates and Ca2+interfere with each other because of the low solubility of calcium phosphates. The need to keep cytosolic Ca2+ low forced cells to restrict Ca2+signals in space and time and to develop energetically favourable Ca2+ signalling and Ca2+microdomains. These steps in tandem dominated further evolution. The ATP molecule (often released by Ca2+-regulated exocytosis) rapidly grew to be the universal chemical messenger for intercellular communication; ATP effects are mediated by an extended family of purinoceptors often linked to Ca2+ signalling. Similar to atmospheric oxygen, Ca2+ must have been reverted from a deleterious agent to a most useful (intra- and extracellular) signalling molecule. Invention of intracellular trafficking further increased the role for Ca2+ homeostasis that became critical for regulation of cell survival and cell death. Several mutually interdependent effects of Ca2+ and ATP have been exploited in evolution, thus turning an originally unholy alliance into a fascinating success story.

Dear Jing,

thanks for the very interesting report on the role of calcium. But today I respond to your encouraging message of October 6 and believe me I am flattered by the fact that you wrote to me "I am going to talk to you in a near future". I am moved!

I apologize for not having written to you before but here in the university I have had so many things to attend to, even exciting, because we have submitted a our manuscript to Nature Review Neuroscience which shows that myelin supports and speeds up nerve conduction because it introduces large amounts of ATP in the neuron: Who does the ATP do? A system present in myelin which in turn derives from the endoplasmic reticulum of oligodendrocyte. We have also written to Nature Review Neuroscience that we are fed up with the bullying of reviewers who are almost always hostile towards novelties and who follow a strict conformism, flattened on what we already know, which is then a dull defense of the existing. We also appealed to 2 correspondences that appeared at the end of August on Nature (see attached). If they accept the manuscript we will celebrate for at least a month !!! You see, the criterion that the ER produces aerobic ATP has important applications, like this one of the new role of the myelin we discovered ten years ago.

About your invitation to analyze Fig. 3 of your excellent manuscript which shows that "Mitochondria are the ATP heroes in CHO system for ER" I agree but it is necessary to better point out: 1) the mitochondria are undoubtedly the protagonists of the aerobic synthesis of the ATP but they are not able to produce it themselves as they are protected by a double membrane system. Therefore 2) they export their machinery to the ER in the first place where the OXPHOS can operate without restrains. This is what happens and therefore there is no doubt that the mitochondria are unquestionably lag to the aerobic synthesis of ATP only that the cell to have the fully operational OXPHOS requires that the machinery is transferred to the ER (but also other subcellular structures receive it ). In your Figure 3, as you work with HeLa cells intact, you have a low resolving power and will agree with me that you cannot tell whether the ATP is produced by the Mitochondria or the ER. The insert G is very interesting. You write that "no difference was found for the two groups treated with siRNA after 2-DG addition”. . Fantastic! Here in Genoa we have an advanced experimentation with 2-DG that is metabolized very well by the Shunt operating on the ER and if you want me to tell you everything the first phase of glycolysis does not go as it is written on the textbooks, but follows the shunt with the first enzyme is the hexose 6 phosphate dehydrogenase (H6PD) that unlike the known G6PD (on which I worked for 20 years!) is inserted in the ER and therefore is unlucky for the attention of the enzymologists who normally study soluble enzymes. But I must confide to you that the key enzyme for the production of reducing equivalents by the ER (which feed the OXPHOS on ER) is precisely the H6PD. If it is lacking in humans it is serious trouble (it is lethal even in knokout mice), while if the G6PD is missing only the red blood cells suffer. I stop here because I understand that it takes time to understand all these news ...

I repeat, to your recent message it focuses on the calcium of October 13 I answer later. I am very much interested to hear what you think of all this ... Waiting to hear back from you Yours sincerely,

Sandro

PS: I attach our paper on OXPHOS on ER

Dear Jing,

I thank you for sending me the article "Inseparable tandem: evolution chooses ATP and Ca2 + to control life, death and cellular signing" that I read. I must tell you that this association between Calcium and ATP does not convince me, because while Calcium is not metabolizable, but only if its concentration in the various cellular districts can be varied, ATP is subjected to chemical modifications, ie it is metabolizable. I myself carried out research on Ca++, in particular on calpain (a calcium dependent protease) and with Prof. Carafoli's group in Zurich I did very interesting research, as in a paper produced in collaboration: “Modulation of erythrocyte Ca2 + -ATPase by selective calpain cleavage of the calmodulin-binding domain.” J Biol Chem. 1989 May 15; 264 (14): 8289-96.James P, Vorherr T, Krebs J, Morelli A, Castle G, McCormick DJ, Penniston JT, De Flora A, Carafoli E. who demonstrated in the cell a cycle feedback: if the intracellular calcium increases, the calpain protease activates, making “surgical” cuts on the ATPase Ca pump, removing the site that binds the calmodulin and activating it to the maximum speed of Ca++ extrusion and lower the concentration of cell calcium. A beautiful research that gave me the opportunity to become aware of a fascinating reality. But the relationship with the ATP did not enter into the talk.

Later eager to understand who produces ATP in the photoreceptor disks (absolutely devoid of mitochondria) we published the article "ATP synthesis in rod outer segments of bovine retina by the reversal of the disk Ca (2+) pump" Biochem Biophys Res Commun. 2000 Feb 16; 268 (2): 625-7; Pepe IM, Panfoli I, Notari L, Morelli A, which showed with great evidence that the inversion of the disk Ca (2+) pump determined the synthesis of ATP as it is theoretically possible for simple thermodynamic reasons. Even back then we were eager to understand what the molecular devices that led to the synthesis of the huge amount of ATP needed to support the expensive energy process of phototransduction were and with that objective we later discovered that in reality the disks have all the OXPHOS machinery and produce with it aerobic ATP in large quantities.

In light of this publication of ours in 2000 I ask you: won't it be that the ATP you see on the ER is synthesized for a reversal of the SERCA ATP ase present on the ER? The ATP then must bind the Mg, which is absolutely similar to calcium (both are of the second group), but discriminates with great specificity, just as all the molecules that bind calcium do not bind Mg. Furthermore, the precious chaperon molecules that use Magnesium must also bind Potassium, and this is probably one of the reasons why sodium must be expelled from the cell to be replaced by K +. Certainly Ca++ and ATP are two separate worlds that still have so many mysteries.

With my best, your sincerely,

Sandro

Apology for being busy these days Sandro -

I have a short answer to your nice question " won't it be that the ATP you see on the ER is synthesized for a reversal of the SERCA ATP ase present on the ER? "

Re: It is theoretically not possible, as the ATPase domain on the SERCA is on the cytosolic leaflet of the ER membrane. Even if ATP is generated through reversal SERCA reaction, it doesn't contribute to the ER pool unless it is transported across the ER membrane.

Thanks for your nice introduction and please allow me more time to digest your message.

Best,

Jing

@Dear Jing,

you don't have to apologize at all. You know, I'm retired and I have much free time because relieved of academic obligations. I understand that those who are in service has shrunk time to devote to research. Rather. It comforts me a lot that you want to consider the topic with adequate time. Your objection to SERCA sideness is correct and in fact the ATP that could be synthesized by SERCA inversion would be found in the cytosol and not in the ER lumen.

However there is evidence that external ATP to a membrane can pass through the membrane with mechanisms yet to be determined, and certainly ANT independent. Such a process would occur across the plasma membrane of certain tumor cells, but there are no specific reports but rather is the result of a born speculation in our lab. The crux of this speculation is the following: on the ER membrane there is the mitochondrial ATP synthase which synthesizes ATP in the lumen and exists the V-Type ATPase which hydrolyses ATP in the cytosol. I state that I do not believe that the V-type is active in pumping protons into the lumen at the expense of cytosolic ATP (as people think) or the simple reason that I do not see the reason to acidify the ER lumen at the expense of Precious ATP…I rather think that you synthesize ATP as it does in the Archea from which it evolved. At this point, if the rotors of the two ATPase-synthetase interact, they couple with mechanical coupling and work as two gear wheels. If on one hand there is an excess of ATP, on that side the ATP is hydrolyzed and by mechanical coupling the ATP is synthesized on the other side. I enclose some slides that illustrate this theoretical coupling, starting from the observation that the ATPase often appears beface on the two sides of the membrane, as in Slide 1 and 2. Start the slide 4 animation. I think you will find the whole intriguing ... In the case of the ER from the cytosolic side we would have the V-Type, but in the slides is not indicated. But I understand that I'm putting too much material on you and don't worry about critically analyzing it for the moment. I like to take bold assumptions. Then experiments after will confirm or refute them.

With my best,

Sandro

Alessandro Morelli

Dear Sandro,

Thanks for your understanding.

In fact I dug a bit more into the topic of ER internalized mitochondria components, and found the following study that might be also of your interest -

Fusion of the Endoplasmic Reticulum and Mitochondrial Outer Membrane in Rats Brown Adipose Tissue: Activation of Thermogenesis by Ca2+

Article Fusion of the Endoplasmic Reticulum and Mitochondrial Outer ...

However, the authors concluded that Ca2+ did not contribute to ATP production under neither scenarios. Nevertheless, I found this an interesting example of how complex and versatile biological systeems can be.

More later.

Best,

Jing

Dear Jing,

thank you very much for the paper that I already knew. In this regard, I must tell you that I have filed a substantial number of papers on the topic Mitocondri-ER-Ca2 +. I send you one that I think may be of interest and which interests me very much because it reinforces the concept that myelin contains OXPHOS machinery which comes from the oligodendrocyte ER which in turn imports it from the mitochondria. In reference to the PlosOne paper that you tell me, I find it right that calcium does not contribute to the synthesis of ATP. Moreover the preparations of mitochondria BAT produce ATP which is 2100 nmole / mg mit / 20 min high which reported to our conditions becomes (except errors because the authors do not specify the conditions well) about 500 nmoles / mg prot mit / min which is high and it's just what we see in platelet ER. Given that the ER is stuck to the mitochondria, I believe that their mitochondria preparations are very rich in ER and one can reasonably suppose that it is this ER that synthesizes so much ATP. Keep in mind that isolated mitochondria produce at most 10-20 nmol ATP / mg prot mit / min, far from 500!

I must also add that the potential indicators do not provide the membrane potential but the degree of protonation of membrane buffers inherent in the proteolipid component of the membrane itself. Moreover, the ATP is not synthesized thanks to the proton translocation to the proton current in charge but not in mass (Grottuss mechanism) which forms circuits all internal to the membrane. This was elucidated in our recent Open Biology paper (2019; 9 (4): 180221. Doi: 10.1098 / rsob.180221 "An update of the chemiosmotic theory as suggested by possible proton currents inside the coupling membrane. "). I'll tell you that our exchange of ideas gratifies me so much... Looking forward to meeting your thinker,

With my best,

Sandro

Dear Jing,

I'll be back after a long time. Our 2019 conversation was very inspiring.

In these years I have continued to study and I would like to point out to you my last Open Biology paper in which it identifies VDAC also in cyanobacteria. You can also see John Hewitt's review on medicalkXpress:

https://medicalxpress.com/news/2022-01-myelin.html

I would like to point out this review written by John Hewitt for its clarity of presentation and for the focus on the innovations that our Open Biology article has introduced.

It is also explained in an incisive form that:

· lipids can act as a gas sponge;

· the radial permeation of metabolites through the concentric multilamellar structures can occur through the non-specific VDAC channel;

· the mitochondria are characterized by allotropy or rather how the mitochondria fuse their internal membranes with other membranes and therefore the mitochondria, although not morphologically distinguishable, in reality their function is present, as happens in myelin.

In scientific practice it may happen that certain ideas are overcome even as a result of hard comparisons / disputes. One idea that needs to be overcome is that myelin plays the role of an "electrical insulator" and John Hewitt illustrates this brilliantly.

Any comment / observation is very welcome.

Alessandro M. Morelli

Prof. Alessandro Maria MORELLI e.mail: [email protected]; [email protected]

Phone Mobile: +39 347 085 22 92

www.biochemlab.it

Imagination is more important than knowledge

Albert Einstein

Aphorism I: Conformism penalizes the advancement of science where it induces us not to depart from what we already know, or rather we think we know, and prevents us from seeking new realities dispersed in the immensity of what we do not know.

Aphorism II: Biology is governed by molecules and therefore is quantized while to study it man resorts to the wear and tear of his mind that leads him to build many speculations that distance him from the discreet and material reality of life.

Dear Alessandro, here it is clearly shown how the myelin sheath accelerates the passage of the impulse.

https://fissi.ru/wp-content/uploads/2020/05/saltatory-conduction.gif

Dear Lev Verkhovsky,

the whole world adopts the scheme of the action of myelin for the acceleration of the impulse. What you sent me is a descriptive scheme and that's fine but ... what is the molecular mechanism that supports it? With my group I proposed a new interpretation that attributes to myelin the supply of massive ATP to the axon and this allows to totally simplify the chemical-physical criteria that underlie the impulse itself. Our paper (which I am attaching) is dramatically simplifying because these criteria (the Hodgkin-Huxley-HH model) simply ... remain unchanged. Furthermore, this action of myelin is in line with our latest Open Biology 2021 papers:Article Myelin sheath and cyanobacterial thylakoids as concentric mu...

With the pleasure of continuing our correspondence,

best wishes,

Sandro

Dear Alessandro Morelli,

I think that you are trying in vain to refute the jump-like mechanism of transmission of impulses that the myelin sheath provides. This is not a question of biochemistry, but more a question of physics.

But, as the textbooks say, myelin performs several functions, and here your idea that myelin supplies ATP to the axon is quite plausible.

Dear Lev Verkhovsky

I do not believe the gif you provided is a proof of a saltatory conduction.

Best rregards

Of cause not, just an illustration. I don't understand the reason to doubt in a jump-like conduction.

A reason Lev Verkhovsky ?

Short-circuit with other neurons! ;-)

Bernard Delalande

Probably, neurons interfere with each other, but neural networks somehow know how to adjust themselves in conditions of electrical and chemical noise. But I am not an expert in these matters.

Yes Lev Verkhovsky , they do interfere and that is unlikely.

Poor noise immunity and near zero transmission.

Neurotransmitters also diffuse at other neurons, a whole Bedlam. But I believe there is a good noise immunity.

I will answer with a question, Lev Verkhovsky : Why does the neuron use neurotransmitters when it could use a simpler and (safer?) way: electricity?

Probably, chemical signaling arose earlier evolutionarily, then electrical signaling was built into it.

I don't think so: jellyfish seem to prove it. Not far from 500 million years old.

Maybe I wasn't clear. I note that saltatory conduction is a reality: the impulse accelerates when the nerve is wrapped in the myelin sheath. There is no doubt. It's a fact. As for the interpretation of the process, the chemical-physical reality tells us that things are different from what is written in the textbooks. It is above all a question of chemistry because the impulse moves along the axon with the well-tested Hodgkin & Huxley (HH) scheme, i.e. the succession of Na pumps and then K voltage gated which must have the right ion distribution to work. which is maintained thanks to the Na / K pump which consumes large amounts of ATP that ... someone has to supply. The axon alone has little ability to regenerate ATP so the pulse goes slow but if it is myelinated it receives a lot of ATP and therefore the pulse goes faster. So is a chemical question. In a matter that exhibits chemical reactions, only physical criteria are hardly applicable, confirming what the writer Primo Levi said that "we are all chemistry". My model predicts that the more coils there are, the more ATP goes to the axon and therefore the faster the impulse runs, while the traditional model that attributes the role of "electrical insulator" to myelin does not contemplate it. Besides all, it is extremely simplifying because the HH model does not change with myelination.

The idea of ​​"electrical insulation" took shape from the 1949 Huxley & Stamply paper that I am attaching. It should be noted that the authors themselves are extremely cautious in proposing the hypothesis of the "electric circuit" to the point of attracting Hodgkin's ideas to it. In fact on page 316 it says "The principle of the method was suggested by Mr AL Hodgkin of Cambridge, who pointed out that, if current can enter or leave the axis cylinder only at the nodes of Ranvier, the current along the axis cylinder must be the same at all points in any one internode at any one moment". It seems that they are unwilling to attribute to themselves the authorship of this idea that seemed bizarre to themselves ...However, their idea has been substituted over time by others, such as the potassium siphoning hypothesis. So many hypotheses mean that none are satisfactory. Furthermore, the action of "electrical insulator" would require a direct contact between axon and myelin sheath and instead the periassonal space exists in the middle but then the theory was adjusted with the idea of ​​the "double electric circuit" as in the recent paper: Cohen CCH, Popovic MA, Klooster J, Weil MT, Möbius W, Nave KA, Kole MHP. "Saltatory Conduction along Myelinated Axons Involves a Periaxonal Nanocircuit" Cell. 2020 Jan 23; 180 (2): 311-322.e15; PMID: 31883793. I find this extremely complicated. I know that Nature has simple solutions. It is humans who are attracted to elaborating complex thoughts ...

Dear Alessandro Morelli

I do not believe in the HH model. I don't believe in an electrical circuit that can work in salt water. I do not believe in the myth of electrotonus.

He did accelerate:

Article Another Train Paradox: May the Myelin Be with You!

Dear Sirs,

For the spike to move along the axon, no energy supply is required: the axon consumes pre-stored energy in the form of a transmembrane potential. And after the passage of the impulse, energy is required to restore the potential again.

BD:

Dera Lev Verkhovsky and Alessandro Morelli

I totally agree with the first part of your answer.

And I also agree with the second statement but, but...

1/ The ions physically move in this current and are not guided by any conductor, whereas in an electric circuit, the circulation is electronic and the metallic atoms remain immobile. Your electric current has every chance of vanishing with the ions close by where it occurs: That's my short circuit.

Ask an electronics engineer what he thinks of your idea of an electrical circuit in a wet and salty environment...

2/ Concerning saltatory conduction:

Imagine an observer observing a car on a circuit: He measures its speed by the time he can see the car at a given point: He observes it for a time t1. A little further on the car comes out of a tunnel and is observed for a time t1 (normal) but he also observes that the duration of the passage through the tunnel is much shorter than t1.

He sees two cars!!!

This is the paradox of saltatory conduction because as soon as the duration of propagation under the myelin is less than t1 (duration of the spike) it is obligatory to accept that there are several spikes generated and the conduction is not saltatory but reproduced at each node and one must accept that the previous one is always visible during the whole duration of t1.

Best regards

Let`s continue, Sirs.

The spike occurs only at the node of Ranvier and propagates in it. It then disappears (it doesn`t move under the myelin). But the electromagnetic field from this spike reaches the next node of Ranvier and a new spike appears there. That's how the jumps go.

Dear Lev Verkhovsky

You can continue to be irrational in your reasoning I like contradictions.

What is the probability that there is a node of Ranvier closer than the next one you consider? 100%.

Don't forget that axons are parts of nerves that contain thousands of axons that are a few microns apart.

Why wouldn't the electromagnetic field go to the nearest node on an axon closer than the next node?

Why shouldn't the facts we observe in real life be applicable to biology?

Take a high voltage generator and a moving electrode that you approach from 3 ground terminals that are more or less close together: Does the flash/discharge always go to the furthest one? Never: There is no electrical circuit but a transient circuit is formed which is always the shortest.

https://www.youtube.com/watch?v=wKG0ZyhHDfE

These questions of yours are technical in nature and do not address the jump mechanism itself. I think that the field effectively spreads only ALONG the axon (thanks to the insulator - myelin), and quickly fades in other directions.

Sorry, but I hear arguments that revolve only on the physicality of how the impulse moves. You forget that biochemistry underlies everything. The brain consumes much more energy than other organs and it is necessary to understand where this energy is spent. The "impulse" that travels along the axon is a potential inversion due to the altered destribution of the Na + and K + ions, impulse that move like a wave and the HH model is absolutely acceptable and we have to think about this. Why should the impulse change when it enters the "tunnel", that is, it is surrounded by myelin. It is necessary to keep your feet on the ground and take into account the chemical / physical nature of this impulse which can progress if the Na / K pump works properly on the membrane. If that does not consume ATP it stops and goodbye impulse.

Then saying that the moving ions are electric current upsets the fundamentals of electrochemistry. The ions move, peraltyro slowly, only by electrophoresis and are deposited on the electrodes. In the electric current only the charge moves but not the mass and with a speed close to that of light. It is evident beyond a reasonable doubt that in the axon, both myelinated and unmyelinated, we cannot speak of electric currents. They do not exist. That's all. Therefore it cannot even exist some material entity to "isolate" them.

I inform you that I will avoid this discussion because I see that there is a lack of passion to move towards new models that are more satisfying than the current ones which, to quote Douglas Fields (Science, 2014, attached) are "fried metaphors".

If you want to continue the discussion between you, go ahead and do so.

>>Why should the impulse change when it enters the "tunnel", that is, it is surrounded by myelin.

Do you think the spike moves under the myelin from one node of Ranvier to the next? No, it simply disappears at the entrance to the myelin region, because the sodium current can no longer enter the axon.

Dear Alessandro Morelli and Lev Verkhovsky

Your answers show the complexity of the phenomenon and all the aspects related to it.

It is possible to approach the biophysical principles without momentarily ignoring the biochemical aspect.

It is obviously necessary to link all the aspects by reliable but above all scientific relations.

The HH model is a model that operates on a false scientific basis and on facts that are not proven.

It is possible to make an axon function/fire several thousand times without ATP.

Example: the external potassium level is about 4mM, if we raise it to 10mM, we die because the intra-cellular level of the myocardium will increase and yet our old HH model imposes a potassium output...

Look for the error!

I`ve already said what I could on this question, so I'm done now.

Merci & Grazie.

I am quoting an Article Non-linear Conductance, Rectification, and Mechanosensitive ...

`It comes as a profound surprise that appearance of channellike conduction events can also be seen in pure lipid membranes in the absence of any proteins and macromolecules, i.e., in the complete absence of any single molecule that could act as a channel`

This was Tasaki's prediction. I think the hypothesis of Mikelsaar offers a specific molecular model that allows understanding this phenomenon

Preprint Bioprotonics

Dear Lev Verkhovsky

This is a possible hypothesis that needs to be explored further. I am not at all a specialist in bio-membranes. I am interested in the phenomena and in finding a better scientific explanation of them.

Mikelsaar's work needs to be highlighted and I am sure to quote it in the final article of "Brilliant Neuron".

The work of Alessandro Morelli is very interesting as it provides an important building block that is missing from the HH model: oxygen and energy consumption but here too there are competing theories (murburn concept by Kelath Murali Manoj ) that can explain the results.

Хорошего дня

Bernard

Dear Bernard Delalande Totally agree with you. My goal is to draw attention to Michelsaar's conjecture: it was proposed over 30 years ago and has gone unnoticed.

Bon chance.

Bernard Delalande, do you know the article from Sci. Amer. 2018, April (pp.74-81) `The Brain, Reimagined` by Douglas Fox?

https://static.scientificamerican.com/sciam/assets/File/OSQ318_Revolutions.pdf

Not yet.

Chère Bernard Delalande , je pense que cet article est très intéressant.

There is a lot of important information to consider. I see a connection with the Mikelsaar model (I will explain later).

Chère Bernard Delalande I posted a paper on this topic

Preprint The Nerve Impulse: Restructuring Waves and Electrical Currents

Hello Lev Verkhovsky ,

I will study the matter carefully but I must admit that at the moment I am totally overwhelmed by my job: physiotherapist.

Dear Lev Verkhovsky

I have read the "brain reimagined" which talks about @https://www.researchgate.net/profile/Thomas-Heimburg theory which I agree with almost entirely.

I totally agree with him: there is no way to reconcile it with Hodgkin and Huxley. It would be like saying that the Earth is both flat and round: there is one theory that is false and unfortunately it is the one that is taught.

However, Heimburg's theory does not work for myelinated fibres and he does not explain the subtreshold responses. Nor does he explain how his model can be electrically triggered. I have developed answers that fill in these gaps.

Morning dear Bernard Delalande

>>>I have developed answers that fill in these gaps.

Could you please express them in a nutshell?

1/I think it is enough to consider the action of the proteins that are in and under the membrane. They contain ions that can be mobilised by a current.

2/Water

I'll quote a statement with which I fully agree:

“To advance our understanding of how nervous systems operate it is important to develop comprehensive models where electrical, chemical, and mechanical energies are not compartmentalized from one another, but rather cooperate in a synergistic manner to regulate neuronal excitability and signaling. By starting to consider the interplay between electrical, chemical, and mechanical energy, new paradigms for understanding and studying the biophysics of neural systems will advance our comprehension of brain function” (Mueller and Tyler, 2014, p. 3).

Article Thinking About the Nerve Impulse: The Prospects for the Deve...

I know the papers 2019 of the Druchars group "Thinking About the Nerve Impulse: The Prospects for the Development of a Comprehensive Account of Nerve Impulse Propagation" and had a correspondence with him. I do not agree that the Hodgkin-Huxley (HH) model is outdated because it is based, in the non-myelinated nerve, on existing proteins, the Na and K voltage gate channels and is connected to the fact that the nerve impulse is energetically very wasteful. In fact, the propagation of the impulse reduces the difference in concentration of the Na and K ions on the sides of the plasma membrane, a difference that is restored only with the work of the Na K pump which consumes a large amount of ATP. I repeat that what happens must be linked to the energies at stake in order to respect the first principle of thermodynamics. The HH model is confirmed by our discovery made in Genoa that myelin "feeds" the axon with ATP for which the physical chemical nature of the impulse does not vary in entering a myelin sheath, as we emphasized in our 2020 paper "Myelination increases chemical energy support to the axon without modifying the basic physicochemical mechanism of nerve conduction "attached. Furthermore, the role of myelin, a reactor with a high lipid content that allows a radial diffusion of the chemical compounds metabolized by it (see our paper 2021 "Myelin sheath and cyanobacterial thylakoids as concentric multilamellar structures with similar bioenergetic properties" -attached) present not only in the nervous system. I want to specify that it is believed that the Na and K voltage gate channels are present only at the Ranvier node but this has been refuted (I can produce the bibliography that proves it). Moreover, the nerve is born unmyelinated with its Na and K voltage gate channels: it is not clear how myelination can move these channels to the node. Le propriet energetihe della mielina sono ben documentate con misure di laboratorio (see our paper 2021 "Efficient extra-mitochondrial aerobic ATP synthesis in neuronal membrane systems"-attached).

Overall it seems to me that in Genoa we have built a coherent picture of nerve impulse transmission and the crucial role of myelin that is based on exhaustive experimental quantitative measures.

PS: I am sending this message to Benjamin Drukarc hoping to involve him in this stimulating discussion.

Dear Alessandro Morelli ,

Science is not based on beliefs but on facts which must be explained by logical and scientific theories.

To believe in the HH model is to believe in a constant output of the K of the cell but:

The Na/K pump when inactivated, the K remains constant in the cell for... hours.

Logic? No.

The cell during its growth brings in potassium because its volume increases.

How does the HH model deal with this fact?

How does a potassium injected in the blood plasma become dangerous for the cell even with minimal concentrations?

How does the HH model deal with this fact?

etc...

but I still agree with the other facts.

another example Alessandro Morelli :

If the Na/k pump is well located in the membrane then it cannot work because it will pump out the K+ ions against the Na+ ions that have just entered. The concentrations at a few nanometres will not change, because only the nearest ions will be mobilised.

And furthermore, the permeability to Sodium is a fraction of a % of that of Potassium so Sodium does not enter... So the pump cannot pump Na+ ions that do not enter.

Dear Alessandro Morelli ,

This is a starting situation for the HH model. Do you really think that the ions will not interact with each other and disrupt the beautiful theory where each ion species is independent of the others?

Now try to get them to move to fit the theory... If you can do it, you are stronger than the simulation or physics!

Best regards

Bioenergetics requires radical changes

The research activity carried out by the Morelli-Panfoli-Ravera-Calzia group (Genoa University, Italy) highlights that many basic concepts of biochemistry require a radical update. Since scientists can communicate with each other only if they refer to the same paradigms, this must be premised in any scientific debate and dissemination activity. The proposed paradigm changes are set out below:

1) The history of mitochondria suffers from too many assumptions that have never been verified. Since mitochondria contain a significant number of molecules that carry out Oxidative Phosphorylation (OXPHOS) with the coupled recharge of ATP (i.e. the transfer to ADP of a residue of orthophosphoric acid with the formation of ATP) in the 1950s everyone believed that the mitochondria held the exclusive supply of ATP to the cell. However, since laboratory measurements denied this assumption (isolated mitochondria produce about 10 nanomoles of ATP / min / mg. Of protein, that is, very little), the P / O ratio was introduced around the 1960s to evaluate the efficiency of mitochondria. A methodological error that still weighs on the study of mitochondria. In fact, the P / O ratio can also be suitable to indicate ATP production capacity but, being the ratio between two flows, the ATP produced and the atomic oxygen consumed, the P / O ratio is a dimensionless quantity completely independent of the real fluxes of metabolites. The P / O ratio can also fall within the canonical values, but the ATP recharge can also be insignificant.

2) The group of biochemists at the University of Genoa experimentally confirmed what was stated in point 1) but also verified that the mitochondria, while not producing ATP for the cell - therefore would be refuted a pillar of bioenergetics - however, they perform an even more important function: the microvesiculation of the internal membrane with the production of microvesicles-exosomes chargo that are sent to the intracellular and even extracellular membranous districts to make them capable, the latter, of producing ATP without the drastic limitations linked to the double membrane that surrounds the mitochondrion. Recently, in confirmation of this, Pasquale D'Acunzo's group identified extracellular exosomes that contain mitochondrial devices which he himself called "mitovesicles" (D’Acunzo et al., 2021).

3) Various intracellular structures certainly receive the OXPHOS molecular machinery from the mitochondria i) all the discs of the outer segments of the rods of the retina, which have a significant capacity to recharge ATP (about 400 nanomoles / min / mg of proteins) (Panfoli et al., 2009) and supply - the discs - the energy for the phototransduction process which, as is known, is a process with a high energy expenditure; ii) we have measured the recharges the ATP (about 80 nanomoles / min / mg of protein) (Ravera et al., 2021) by myelin sheath which send ATP to the axon to support the advancement of the nerve signal. We can say in metaphorical language that myelin is like a gigantic mitochondrion that presides over the high energy processed by the brain.

It is understood that from all this more than one current paradigm of biology and neurobiology should be replaced by others as proposed in the recent article (Morelli, 2022).

References

D’Acunzo, P., Pérez-González, R., Kim, Y., Hargash, T., Miller, C., Alldred, M.J., Erdjument-Bromage, H., Penikalapati, S.C., Pawlik, M., Saito, Mitsuo, Saito, Mariko, Ginsberg, S.D., Neubert, T.A., Goulbourne, C.N., Levy, E., 2021. Mitovesicles are a novel population of extracellular vesicles of mitochondrial origin altered in Down syndrome. Sci Adv 7. https://doi.org/10.1126/sciadv.abe5085

Morelli, A.M., 2022. A new way of understanding bioenergetics. Res Featur. https://doi.org/10.26904/RF-142-2921655847

Panfoli, I., Calzia, D., Bianchini, P., Ravera, S., Diaspro, A., Candiano, G., Bachi, A., Monticone, M., Aluigi, M.G., Barabino, S., Calabria, G., Rolando, M., Tacchetti, C., Morelli, A., Pepe, I.M., 2009. Evidence for aerobic metabolism in retinal rod outer segment disks. Int J Biochem Cell Biol 41, 2555–65. https://doi.org/10.1016/j.biocel.2009.08.013

Ravera, S., Bartolucci, M., Calzia, D., Morelli, A.M., Panfoli, I., 2021. Efficient extra-mitochondrial aerobic ATP synthesis in neuronal membrane systems. J Neurosci Res. https://doi.org/10.1002/jnr.24865

Notes written by Alessandro Maria Morelli ([email protected])

Genoa (Italy), 15 September 2022

The question of who actually produces ATP for the cell still awaits an answer today and continues to be a conundrum of biology. In the short notes "Bioenergetics require radical changes" that I attach I have summarized 3 fundamental points to address the problem. Until it is resolved, there is little hope of identifying the causes that trigger diseases such as Alzheimer's and Parkinson's.

I trust that the document will start a stimulating discussion.