THE SYNTAXIN FAMILY OF VESICULAR TRANSPORT RECEPTORS

Syntaxins A and B are nervous system-specific proteins implicated in t he docking of synaptic vesicles with the presynaptic plasma membrane. A family of syntaxin-related proteins from rat has been identified tha t shares 23%-84% amino acid identity. Each of the six syntaxins termin ate with a carboxy-terminal hydrophobic domain that anchors the protei n on the cytoplasmic surface of cellular membranes. The syntaxins disp lay a broad tissue distribution and, when expressed in COS cells, are targeted to different subcellular compartments. Microinjection studies suggest that the nervous system-specific syntaxin 1A is important for calcium-regulated secretion from neuroendocrine PC12 cells. These res ults indicate that the syntaxins are a family of receptors for intrace llular transport vesicles and that each target membrane may be identif ied by a specific member of the syntaxin family.