I tried to find the protein named NaAF, but there is no such protein in any of the protein databases. 

It  (NaAF) won't be present in the database because it remained unnoticed since its discovery due to the following reasons. The NaAF was discovered by us (please see my publications) in mid 1980's as an essential cytosolic regulatory protein (170 k Da mass) of the universal Na, K-ATPase system (Na-pump). The NaAF provided the crucial evidences for us to propose a mirror-image (dual topology) model for the vital P2-ATPase system (with two built-in ion-channels for simultaneous transport of Na and K) that maintains intracellular ionic homeostasis. Since the Post-Albers single topology (one channel) model has been dominating the field for 50 years, our model (published in 1986 in BJ) was ignored. People have been force-fitting the data to PA model in numerous publications since then, until the vital field came to a dead halt around 2010.

I reintroduced the dual topology model in a recent book (2012) followed by F1000 article in 2013( please look at my publications) to revitalize this vital field. My question have been posed based on the following scenario. There are genetic maps available for various animals including human. The DNA sequence of the 170 k Da NaAF and the  alpha-subunit (110 k Da mass) of the Na, K-ATPase molecule will be present in every animal cell. Contrary to the alpha-subunit (wellknown in literature) the NaAF would have large hydrophobic (uncharged) domains. Based on these leads, I thought we could start the databank screening.

Please let me know your thoughts.

Thank you, Pritam.  Please read carefully the following information.

a) The NaAF (170 k Da. mass) is a soluble protein which is present in every cell of our body along with the plasma-membrane bound Na, K-ATPase (Na-Pump), while acting as the regulator cum driver of the Na-Pump.

b) Hence, the data bank on soluble-proteins of the cell type will have the information on NaAF sequence, while the information data on insoluble protein like the α-subunit (110 k Da. mass) of the Na-Pump will be in the membrane protein bank.

c) However, the NaAF sequence remains unknown. Hence, we need to identify the NaAF based on its characteristic molecular properties, with close similarities to its isoform, HAF (80 k. Da. having two identical 40 k Da. subunits) from Soluble-protein data bank. Note that the HAF will be found only in gastric parietal cell (data bank), which drives the Proton-pump for making gastric acid.

d) We know the amino acid composition of the HAF. Based on mechanism of H, K-ATPase activation it is clear that the HAF has a bipolar structure (with opposite orientation of two 40 K Da. subunits) creating a large hydrophilic Ca-binding domain in between.  Comparative studies on cross-activation of the two ATPase systems by the HAF and NaAF suggested similar domain (Ca-binding) structure within the NaAF molecule.

e) The soluble activator proteins (NaAF and HAF) interact with the catalytic subunits of the respective membrane bound ATPase systems facing the cytosol. We studied these in great details.

Hence, based on this information, just discussed, we will have to search the two separate data-banks, one for the Na, K-ATPase system, and the other for the gastric H, K-ATPase system. Both α-subunits of the ATPase are fairly characterized. Note that we are not concerned on the β-subunits at this time.

Please let me know as soon as you will need further clarification on any of the above aspects.

Please google the term "insillico" for the details -- Basically In silico is an expression used to mean “performed on computer or via computer simulation.” The expression in silico was first used in public in 1989 in the workshop “Cellular Automata: Theory and Applications” in Los Alamos, New Mexico. Pedro Miramontes, a mathematician from National Autonomous University of Mexico (UNAM), presented the report “DNA and RNA Physicochemical Constraints, Cellular Automata and Molecular Evolution.” In his talk, Miramontes used the term ”in silico” to characterize biological experiments carried out entirely in a computer.

Our investigation on NaAF will be using this insillico approach.

I want to draw your kind attention to this latest paper on the tissue-based mapping of the human proteome (Mathias et al, 2015 DOI: 10.1126/Science.1260419). This paper would provide helpful leads towards identification of the insoluble (membrane-bound) P2-ATPase system (Na-pump) together with its regulatory protein, the soluble NaAF due to the following.

Among all 32-tissues reported, Brain will be especially helpful for our purpose due to the unique makeup of the protein-coding genes of this tissue. In brain 80% of the proteins are membrane-bound and the rest (20%) in a soluble form.  Thus this, top Oxygen consuming tiny-organ (about 3 lbs.) is enormously enriched in the P2-ATPase pump for the endless transmission of electrochemical neuronal signals, production and trafficking of neurotransmitter vesicles at terminal as well as high production of mitochondrial ATP to meet the top energy demand. The concentration of the soluble ubiquitous NaAF (having 170 k Da mass) will also be equitably very high due its essentiality in Na-pump function.

So, please look into this timely paper for any kind lead in our quest for NaAF in brain function.

The Science publication of Mathias et al 2015 DOI: 10.1126/Science.1260419 just mentioned is attached.