Catalytic domain of the Serine/Threonine Kinase, Atypical Protein Kinase C zeta
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. PKC-zeta plays a critical role in activating the glucose transport response. It is activated by glucose, insulin, and exercise through diverse pathways. PKC-zeta also plays a central role in maintaining cell polarity in yeast and mammalian cells. In addition, it affects actin remodeling in muscle cells. PKCs are classified into three groups (classical, atypical, and novel) depending on their mode of activation and the structural characteristics of their regulatory domain. aPKCs only require phosphatidylserine (PS) for activation. The aPKC-zeta 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.