May be involved in signal-transduction pathways related to the control of brain development. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Mainly expressed in brain, with small amounts in heart, liver, kidney and heart. Detected in developing brain with a peak at E18. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.