May be involved in the control of neuronal proliferation or migration in the brain of embryos. 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. Expressed predominantly in the developing neural structures. Levels gradually increases from 36 to 144 hpf. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.