Displays a modest preference for threonine over serine residues. Does not phosphorylate myosin II, however can phosphorylate MBP, in vitro. May be involved in the regulation of myosin II function during cytokinesis. Overexpression leads to impaired cell proliferation in suspension culture and fails to develop beyond the mound stage. Both overexpression and absence of the gene can result in defects in cytokinesis and alterations in myosin II abundance and assembly. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Autophosphorylation activity enhanced by calcium/calmodulin. Interacts with calmodulin; in the presence of calcium. Enriched adjacent to large spherical structures such as contractile vacuoles and Golgi-like structures (perinuclear). Expressed continuously throughout development. Low expression (at protein level). Autophosphorylated, in vitro. Impaired development, multinucleation, fruiting body formation that is delayed by 36-48 hours during the development in addition to stalks and spores that are thin and smaller. Belongs to the protein kinase superfamily. Alpha-type protein kinase family. ALPK subfamily.