Mature mammalian RBCs are denucleated. It means that RBCs cannot code for any protein. We also know that Glycolysis occurs in RBCs but from where RBCs did they get all the enzymes needed for glycolysis when they don't have nucleus.
If you look into erythropoiesis you see that erythrocytes have nucleated progenitor cell called proerythroblasts.
So, Do you think enzymes formed during erythropoiesis are enough for 100-120 days of life time of mature erythrocytes.
Matthias is right. Actually normal red cells are replaced before they become metabolically deficicent and this is particularly true for the glycolytic pathawy. The major signal for red cell removal is the appearance of neo-antigens on their external surface.
Till Reticulocyte phase, RBC has nuclear material.
Joanna explanation is good.
@jacques Elion , how this neo-antigens come ? What are they ?
Neo-antigens arise from aging of the RBC membrane. Actually the metabolic activity indeed decreases slowly with age of the cell. As Joanna mentioned, synthesis of reduced glutathione is critical to maintain a reducing environment and protect all the cell components from the oxidative stress. Glutathione metabolism is the first to decrease (way before glycolysis) and the oxidative stress increases. Oxidative damage of the RBC membrane triggers the appearance of neo-antigens. One of the most documented is Protein Band 3 clustering which creates new antigenic motives at the cell surface, i.e. neo(new)-antigens.
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