The phosphorylation and dephosphorylation of proteins on serine and threonine residues is an essential means of regulating a broad range of cellular functions in eukaryotes, including cell division, homeostasis and apoptosis. A group of proteins that are intimately involved in this process are the serine/threonine(Ser/Thr) protein kinases. MAST4 (microtubule associated serine/threonine kinase family member 4), also known as KIAA0303, is a 2,626 amino acid protein that localizes to the cytoplasm and contains one protein kinase domain, as well as one PDZ domain and one AGC-kinase C-terminal domain. Expressed at high levels in most adult tissues, including testis, colon and small intestine, MAST4 uses magnesium as a cofactor to catalyze the ATP-dependent phosphorylation of target proteins. Multiple isoforms of MAST4 exist due to alternative splicing events.
KIAA0303; mast4; Microtubule-associated serine/threonine-protein kinase 4