The MAK10 gene encodes a 733-amino acid protein with several regions of similarity to T cell receptor alpha-subunit V (variable) regions in yeast. 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. This complex functionally co-assembles in mammalian cells to regulate cell proliferation and is essential for embryonic development, at least in part through the regulation of target of rapamycin (TOR) signaling events. At least two isoforms of MAK10 are known to exist.