Publication Date:
1992-03-27
Description:
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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Colombo, M I -- Mayorga, L S -- Casey, P J -- Stahl, P D -- AI 20015/AI/NIAID NIH HHS/ -- GM 42259/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1992 Mar 27;255(5052):1695-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Biology and Physiology, Washington University, School of Medicine, St. Louis, MO 63110.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1348148" target="_blank"〉PubMed〈/a〉
Keywords:
Biological Transport
;
Endocytosis
;
Endosomes/*physiology
;
GTP-Binding Proteins/chemistry/*physiology
;
Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology
;
Guanosine Diphosphate/pharmacology
;
Guanosine Triphosphate/metabolism
;
Intracellular Membranes/*metabolism
;
Macromolecular Substances
;
*Membrane Fusion/drug effects
;
Organelles/*physiology
;
Peptides
;
Wasp Venoms/pharmacology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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