MAK10 protein regulates the proliferation of smooth muscle cells. The mammalian homologue of yeast MAK10, also known as EGAP, is one subunit of a novel N-terminal acetyltransferase (NAT) that is highly conserved among vertebrate species. It is expressed in a variety of tissues in the developing rat embryo but restricted in expression in the adult, remaining detectable only in tissues undergoing continual cell renewal or in cells responding to pathological injury. The MAK10-NAT complex is an essential regulatory enzyme controlling the function of a subset of proteins required for embryonic growth control and vessel development.