Evolutionarily conserved glucosamine-6-phosphate acetyltransferase; required for multiple cell cycle events including passage through START, DNA synthesis, and mitosis; involved in UDP-N-acetylglucosamine synthesis, forming GlcNAc6P from AcCoA; serotonin N‐acetyltransferase (SNAT)-like homolog that catalyzes the in vitro conversion of serotonin to N-acetylserotonin (NAS), and 5‐methoxytryptamine (5-MT) to melatonin, linking this N‐acetyltransferase to melatonin biosynthesis