Vesicle Associated Membrane Protein 7 (VAMP7)

Exocytosis of vesicle contents requires fusion of opposing membrane layers, and the highly conserved proteins of the SNARE family are crucially involved in this process. SNAREs localized to the vesicle membrane, or v-SNAREs, include VAMP7, and SNAREs localized to the target membrane, or t-SNARES, include the SNAPs and the syntaxins. The SNARE proteins assemble into a core complex of bundled helices and thereby contribute to membrane fusion. The gene, designated SYBL1, encodes a 220-amino acid polypeptide of 25 kD with 60% similarity (37.5% homology) to an unpublished Arabidopsis gene sequence. SYBL1 was found, unlike all Xp pseudoautosomal genes studied to that time, to undergo X inactivation. In addition, it is also inactive on the Y chromosome, thereby maintaining dosage compensation in an unprecedented way.