CYSTEINE-STRING PROTEINS AS TEMPLATES FOR MEMBRANE-FUSION - MODELS OFSYNAPTIC VESICLE EXOCYTOSIS

Cysteine-string proteins are relatively small, cysteine-rich component s of synaptic vesicle membranes. Recent investigations demonstrated th at at least 11 of the 13 cysteine residues of the Torpedo cysteine-str ing protein are fatty acylated. This exceptional level of fatty acylat ion occurs along a short stretch (less than 25 residues) of amino acid s which are flanked on either side by very polar amino and carboxy ter mini. This amphipathic structure may have unique capabilities to catal yze events at membrane interfaces. We propose two distinct pathways to explain how these capabilities might subserve membrane fusion and exo cytosis.