AMPKalpha1 is a protein encoded by the PRKAA1 gene which is approximately 64 kDa. AMPKalpha1 is localised to the cytoplasm and nucleus. It is involved in RET signalling, mTOR signalling, AMP-activated protein kinase signalling, the regulation of TP53 activity and longevity regulating pathway. It is a catalytic subunit of AMP-activated protein kinase, an energy sensor protein kinase that plays a key role in regulating cellular energy metabolism. In response to reduction of intracellular ATP levels, it activates energy-producing pathways and inhibits energy-consuming processes such as protein, carbohydrate and lipid biosynthesis, as well as cell growth and proliferation. AMPKalpha1 is expressed in the nervous system, liver, blood, intestine and kidney. Mutations in the PRKAA1 gene may result in obesity. STJ91580 was affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogen. This polyclonal antibody detects endogenous levels of AMPKalpha1 protein.