Cleavage of neuronal synaptosomal-associated protein of 25 kDa by exogenous matrix metalloproteinase-7

J Neurochem. 2007 Aug;102(4):1256-63. doi: 10.1111/j.1471-4159.2007.04625.x. Epub 2007 May 1.

Abstract

Matrix metalloproteinases (MMPs) belong to a family of zinc dependent enzymes best studied for their role in cancer and inflammation. Though MMPs typically target extracellular proteins, here we show that MMP-7, an MMP family member which lacks a C-terminal hemopexin-like domain, can cleave an intraneuronal protein that is critical to vesicular fusion and neurotransmitter release, synaptosomal-associated protein of 25 kDa (SNAP-25). Western blot analysis using an N-terminal specific antibody on extracts from cultured neurons suggests that cleavage occurs towards the C-terminal portion of SNAP 25. Additional studies with recombinant SNAP-25 demonstrate that cleavage occurs at amino acid 129. The ability of MMP-7 to cleave SNAP-25 is diminished by chlorpromazine and phenylarsine oxide, inhibitors of clathrin dependent endocytosis. Together, these results imply that exogenous MMP-7 can access an intraneuronal substrate and suggest that additional studies may be warranted to determine if SNAP function is impaired with brain inflammation.

Publication types

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

MeSH terms

  • Animals
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Clathrin / metabolism
  • Embryo, Mammalian
  • Endocytosis / drug effects
  • Humans
  • Matrix Metalloproteinase 7 / pharmacology*
  • Neurons / drug effects*
  • Rats
  • Synaptosomal-Associated Protein 25 / metabolism*
  • Time Factors

Substances

  • Clathrin
  • Synaptosomal-Associated Protein 25
  • Matrix Metalloproteinase 7