Plays a role in cytokinesis. Required for KIF14 localization to the central spindle and midbody. Probable RHO/RAC effector that binds to the GTP-bound forms of RHO and RAC1. It probably binds p21 with a tighter specificity in vivo. Displays serine/threonine protein kinase activity. Plays an important role in the regulation of cytokinesis and the development of the central nervous system. Phosphorylates MYL9/MLC2. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts with TTC3 (By similarity). Homodimer (Probable). Directly interacts with KIF14 depending on the activation state (stronger interaction with the kinase-dead form). Additional isoforms seem to exist. A major signal was observed in testis and brain, but it was also detected in thymus, spleen, kidney, heart and lung. Detected at 10.5 dpc with highest expression in the developing central nervous system. After 16.5 dpc expression decreases and at two weeks after birth is restricted to the proliferating neuronal precursor cells in the external germinal layer of the cerebellum and subventricular migratory stream. Death before reaching adulthood, probably due to lethal epilepsy. Mice display severe defects in the olfactory bulbs, the hippocampus, and the cerebellum. These defects appear to result from impaired cytokinesis followed by the induction of apoptosis in specific neuroblast populations. Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family.