Catalytic subunit of the N-terminal acetyltransferase A (NatA) complex which displays alpha (N-terminal) acetyltransferase activity (PubMed:12888564). Acetylates amino termini that are devoid of initiator methionine (By similarity). The alpha (N-terminal) acetyltransferase activity may be important for vascular, hematopoietic and neuronal growth and development (By similarity). Without NAA15, displays epsilon (internal) acetyltransferase activity towards HIF1A, thereby promoting its degradation (PubMed:12464182). Represses MYLK kinase activity by acetylation, and thus represses tumor cell migration (By similarity). Acetylates, and stabilizes TSC2, thereby repressing mTOR activity and suppressing cancer development (By similarity). Acetylates HSPA1A and HSPA1B at 'Lys-77' which enhances its chaperone activity and leads to preferential binding to co-chaperone HOPX (By similarity). Acetylates HIST1H4A (By similarity). Acts as a negative regulator of sister chromatid cohesion during mitosis (By similarity). acetyl-CoA + N-terminal glycyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetylglycyl-[protein] acetyl-CoA + N-terminal L-alanyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-alanyl-[protein] acetyl-CoA + N-terminal L-seryl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-seryl-[protein] acetyl-CoA + N-terminal L-valyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-valyl-[protein] acetyl-CoA + N-terminal L-cysteinyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-cysteinyl-[protein] acetyl-CoA + N-terminal L-threonyl-[protein] = CoA + H(+) + N-terminal N(alpha)-acetyl-L-threonyl-[protein] Component of the N-terminal acetyltransferase A complex (also called the NatA complex) composed of NAA10 and NAA15 (By similarity). Interacts with NAA15 (PubMed:12888564). Component of the N-terminal acetyltransferase A (NatA)/HYPK complex at least composed of NAA10, NAA15 and HYPK, which has N-terminal acetyltransferase activity (By similarity). In complex with NAA15, interacts with HYPK (By similarity). Component of the N-terminal acetyltransferase E (NatE) complex at least composed of NAA10, NAA15 and NAA50 (By similarity). Within the complex interacts with NAA15; the interaction is required for binding to NAAT50 (By similarity). Interacts with NAAT50 (By similarity). The interaction of the NatA complex with NAA50 reduces the acetylation activity of the NatA complex (By similarity). Component of the N-terminal acetyltransferase E (NatE)/HYPK complex at least composed of NAA10, NAA15, NAA50 and HYPK (By similarity). In complex with NAA15, interacts with HYPK; the interaction with HYPK reduces the capacity of the NatA complex to interact with NAA50 (By similarity). Interacts with HIF1A (via its ODD domain); the interaction increases HIF1A protein stability during normoxia, an down-regulates it when induced by hypoxia (PubMed:12464182). Interacts with the ribosome (By similarity). Binds to MYLK (By similarity). Interacts with NAA16 (By similarity). Interacts (via its C-terminal domain) with TSC2, leading to its acetylation (By similarity). Interacts with IKBKB (By similarity). Interacts with HSPA1A and HSPA1B leading to its acetylation (By similarity). Also present in the free cytosolic and cytoskeleton-bound polysomes. Ubiquitous. Expressed throughout the developing brain from 11.5 dpc through 17 dpc, continues to be expressed at P0, but then is down-regulated. Cleaved by caspases during apoptosis. Phosphorylation by IKBKB/IKKB at Ser-209 destabilises NAA10 and promotes its proteasome-mediated degradation. Autoacetylated at Lys-136 which stimulates its catalytic activity. Belongs to the acetyltransferase family. ARD1 subfamily.