|Structure and Function:||
Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is an enzyme of the glycolytic pathway responsible for the conversion of glyceraldehyde 3- phosphate to D glycerate 1,3, -bisphosphate. It is present in high levels in all cells and is often used as a protein normalizing control.
Like many enzymes, GAPDH is now known to execute many different functions in the cell besides its primary function in glycolysis. There is good evidence of the role of this enzyme in apoptosis. Several studies indicate that GAPDH is over-expressed and translocates to the nucleus in response to several forms of cell stress. Of particular importance GAPDH appears to be a monitor of and a signaling component in oxidative stress induced cell death. Nitric oxide S-nitrosylates the enzyme inducing its interaction with the E3-ubquitin-ligase Siah, which translocates GAPDH to the nucleus. GAPDH may also protect cells from apoptosis under some conditions, in particular in caspase-independent cell death and instead deflect the cell to autophagy.
Finally, GAPDH also appears to be involved in the vesicle transport from the endoplasmic reticulum (ER) to the Golgi which is part of shipping route for secreted proteins.
|Disease Associations:||GAPDH may have a role in different pathologies such as prostate cancer, programmed neuronal cell death, and neurodegenerative diseases.|