Catalytic domain of the Alpha subunit of the Serine/Threonine Kinase, AMP-activated protein kinase
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. AMPK, also called SNF1 (sucrose non-fermenting1) in yeasts and SnRK1 (SNF1-related kinase1) in plants, is a heterotrimeric enzyme composed of a catalytic alpha subunit and two regulatory subunits, beta and gamma. It is a stress-activated kinase that serves as master regulator of glucose and lipid metabolism by monitoring carbon and energy supplies, via sensing the cell's AMP:ATP ratio. In response to decreased ATP levels, it enhances energy-producing processes and inhibits energy-consuming pathways. Once activated, AMPK phosphorylates a broad range of downstream targets, with effects in carbohydrate metabolism and uptake, lipid and fatty acid biosynthesis, carbon energy storage, and inflammation, among others. Defects in energy homeostasis underlie many human diseases including Type 2 diabetes, obesity, heart disease, and cancer. As a result, AMPK has emerged as a therapeutic target in the treatment of these diseases. The AMPK subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.
Jiyao W et al.(2023). "The conserved domain database in 2023.",