Transmembrane Protein 27 (TMEM27)

TMEM27 encodes a transmembrane protein that is important for trafficking amino acid transporters to the apical brush border of proximal tubules. It also plays a role in controlling insulin exocytosis by regulating formation of the SNARE (soluble N-ethylmaleimide-sensitive-factor attachment protein receptor) complex in pancreatic beta cells. TMEM27 has an N-terminal signal sequence, followed by a noncatalytic extracellular domain, a transmembrane segment, and a cytosolic domain. The extracellular domain contains an O-glycosylation site and 2 N-glycosylation sites. Human TMEM27 shares 47.8% identity with the C-terminal end of ACE2, but it lacks an ACE2-like catalytic domain. Northern blot analysis of rat, mouse, and human tissues detected a transcript of about 1.8 kb exclusively in kidney.