Evidence of a role for heterotrimeric GTP-binding proteins in endosome fusion.

Journal Article (Journal Article)

Guanosine triphosphate (GTP)-binding proteins are required for intracellular vesicular transport. Mastoparan is a peptide component of wasp venom that increases nucleotide exchange in some classes of G alpha subunits of regulatory heterotrimeric GTP-binding proteins (G proteins). Mastoparan and other compounds that increase nucleotide exchange by G proteins inhibited endosome fusion in vitro and reversed the effects of guanosine 5'-O-(3-thiotriphosphate) (GTP-gamma-S), a nonhydrolyzable GTP analog. Addition of beta gamma subunits of G proteins to the fusion assay antagonized the stimulatory effect of GTP-gamma-S, confirming the participation of G proteins. These results indicate that GTP-binding proteins are required for endosome fusion and in particular that a G protein is involved. Given the function of G proteins in signal transduction, these findings may provide insight into the mechanism by which endosomal vesicles become competent for fusion after their formation at the cell surface.

Full Text

Duke Authors

Cited Authors

  • Colombo, MI; Mayorga, LS; Casey, PJ; Stahl, PD

Published Date

  • March 27, 1992

Published In

Volume / Issue

  • 255 / 5052

Start / End Page

  • 1695 - 1697

PubMed ID

  • 1348148

International Standard Serial Number (ISSN)

  • 0036-8075

Digital Object Identifier (DOI)

  • 10.1126/science.1348148


  • eng

Conference Location

  • United States