Catalytic domain of the Serine/Threonine kinases, Autophagy-related protein 1 and Unc-51-like kinases
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. This subfamily includes yeast ATG1 and metazoan homologs including vertebrate ULK1-3. The ATG1/ULK complex is conserved from yeast to humans and it plays a critical role in the initiation of autophagy, the intracellular system that leads to the lysosomal degradation of cellular components and their recycling into basic metabolic units. It is involved in nutrient sensing and signaling, the assembly of autophagy factors and the execution of autophagy. In metazoans, ATG1 homologs display additional functions. Unc-51 and ULKs have been implicated in neuronal and axonal development. The ATG1/ULK subfamily is part of a larger superfamily that includes the catalytic domains of other protein 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.",