Catalytic domain of Brain-specific serine/threonine-protein kinases 1 and 2
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. BRSK1, also called SAD-B or SAD1 (Synapses of Amphids Defective homolog 1), and BRSK2, also called SAD-A, are highly expressed in mammalian forebrain. They play important roles in establishing neuronal polarity. BRSK1/2 double knock-out mice die soon after birth, showing thin cerebral cortices due to disordered subplate layers and neurons that lack distinct axons and dendrites. BRSK1 regulates presynaptic neurotransmitter release. Its activity fluctuates during cell cysle progression and it acts as a regulator of centrosome duplication. BRSK2 is also abundant in pancreatic islets, where it is involved in the regulation of glucose-stimulated insulin secretion. The BRSK1/2 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.",