Rabbit Polyclonal Antibody to GAPDH
Cat# RPCA-GAPDH

      Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a metabolic enzyme responsible for catalyzing one step in the glycolytic pathway, the reversible oxidative phosphorylation of glyceraldehyde 3-phosphate to produce glyceraldehyde 1-3-bisphosphate. Because GAPDH protein is expressed in large amounts and is required at all times for an important “house keeping” function, levels of GAPDH mRNA are often measured and used as standards in studies of the expression of other mRNAs. Similarly specific antibodies to GAPDH are used to measure GAPDH expression as a protein standard in western blotting experiments. This antibody can be used as a loading control for such experiments, allowing comparison between the expression level of this protein and others in a cell or tissue. Apart from a role in glycolysis, GAPDH may have other roles, such as in the activation of transcription (1). GAPDH is also reported to bind to a variety of other proteins, including the amyloid precursor protein, mutations in which cause some forms of Alzheimer’s disease, and the polyglutamine tracts of Huntingtin, the protein product aberrant forms of which are causative of Huntington’s disease (2,3). The protein may also have a role in the regulation of apoptosis, and interestingly migrates from the cytoplasm into the nucleus when cells become apoptotic (4). The control of this is mediated by NO mediated S-nitrosylation of GAPDH in the cytoplasm which then binds to and stabilizes the Siah1 E3 ubiquitin ligase which enters the nucleus along with nitrosylated GAPDH. Nuclear Siah1 then initiates specific protein degradation events leading to the activation of a nuclear cell death pathway (5). Recently GAPDH was shown to be a substrate for the 5′-AMP dependent protein kinase (AMPK) which results in the redistribution of cellular GAPDH to cytosolic membranes and the inhibition of intracellular transport (6). AMPK is activated as AMP levels increase in response to starvation, and the pathway including GAPDH and transport inhibition apparently conserves cellular energy.
      The immunogen used to raise RPCA-GAPDH was extensively purified pig GAPDH. The antibody has been widely used as a western blotting standard by many labs for many years and is known to detect GAPDH in a variety of mammalian species including human, rat and mouse. It produces a single clean band on western blots of typical cell and tissue extracts We also market a widely used mouse monoclonal antibody to GAPDH, MCA-1D4 with similar properties to RPCA-GAPDH. Mouse select image at left for larger view.