Catalytic domain of Numb-Associated Kinase (NAK)-like Serine/Threonine kinases
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. This subfamily is composed of Drosophila melanogaster NAK, human BMP-2-inducible protein kinase (BMP2K or BIKe) and similar vertebrate proteins, as well as the Saccharomyces cerevisiae proteins Prk1, Actin-regulating kinase 1 (Ark1), and Akl1. NAK was the first characterized member of this subfamily. It plays a role in asymmetric cell division through its association with Numb. It also regulates the localization of Dlg, a protein essential for septate junction formation. BMP2K contains a nuclear localization signal and a kinase domain that is capable of phosphorylating itself and myelin basic protein. The expression of the BMP2K gene is increase during BMP-2-induced osteoblast differentiation. It may function to control the rate of differentiation. Prk1, Ark1, and Akl1 comprise a subfamily of yeast proteins that are important regulators of the actin cytoskeleton and endocytosis. They share an N-terminal kinase domain but no significant homology in other regions of their sequences. The NAK-like 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.",