There's more to life than neurotransmission: the regulation of exocytosis by synaptotagmin VII

Trends Cell Biol. 2005 Nov;15(11):626-31. doi: 10.1016/j.tcb.2005.09.001. Epub 2005 Sep 15.

Abstract

Among the 16 known vertebrate synaptotagmins, only Syt I, IV and VII are also present in C. elegans and Drosophila, suggesting that these isoforms play especially important roles in vivo. Extensive evidence indicates that Syt I is a synaptic vesicle Ca(2+) sensor essential for rapid neurotransmitter release. It has been suggested that the ubiquitously expressed Syt VII also regulates synaptic vesicle exocytosis, despite its presence in several tissues in addition to the brain. Here, we discuss recent genetic and biochemical evidence that does not support this view. Syt VII null mutants do not have a neurological phenotype, and the protein is found on the membrane of lysosomes and some non-synaptic secretory granules, where it regulates Ca(2+)-triggered exocytosis and plasma membrane repair.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cell Membrane / metabolism
  • Exocytosis / physiology*
  • Humans
  • Lysosomes / metabolism
  • Membrane Fusion / physiology
  • Models, Biological
  • Receptors, Calcium-Sensing / physiology
  • Secretory Vesicles / metabolism
  • Synaptic Transmission / physiology
  • Synaptotagmin I / physiology
  • Synaptotagmins / physiology*

Substances

  • Receptors, Calcium-Sensing
  • Synaptotagmin I
  • Synaptotagmins