Specific inhibitors implicate a soluble metalloendoproteinase in exocytosis.

Published

Journal Article

1. Previous studies have demonstrated that exocytosis in adrenal chromaffin cells appears to require zinc-dependent endoproteinase activity. 2. Chromaffin cells have metal-dependent endoproteinases in both the plasma membrane and the soluble fraction of homogenized cells. In order to further study critically the role of metalloproteinase in exocytosis, and prior to purification, we needed to determine which one of several adrenal metalloproteinases is implicated in exocytosis. 3. The studies described here demonstrate that the metal-dependent endoproteinases in these two subcellular fractions can be differentiated by selective inhibitors. In both intact and permeabilized cells, the plasma membrane metalloproteinase, but not the soluble proteinases, is inhibited by phosphoramidon. Phosphoramidon does not block exocytosis in either intact or permeabilized cells. 4. In addition, the plasma membrane metalloproteinase appears to have its catalytic site facing the outside of the cell. 5. Because of these observations the plasma membrane metalloproteinase does not appear to be required in exocytosis. Since soluble metalloproteinase activity is inhibited by proteinase inhibitors at concentrations which block exocytosis, a soluble, and not the plasma membrane, metalloproteinase appears to be required in exocytosis.

Full Text

Duke Authors

Cited Authors

  • Mundy, D; Hermann, T; Strittmatter, WJ

Published Date

  • December 1987

Published In

Volume / Issue

  • 7 / 4

Start / End Page

  • 425 - 437

PubMed ID

  • 3330469

Pubmed Central ID

  • 3330469

International Standard Serial Number (ISSN)

  • 0272-4340

Language

  • eng

Conference Location

  • United States