Uncoupling of Membrane Ruffling and Pinocytosis during Ras Signal Transduction

Activation of Ras stimulates cell surface membrane ruffling and pinocytosis. Although seen as coupled events, our study demonstrates that membrane ruffling and pinocytosis are regulated by distinct Ras signal transduction pathways. Ras controls membrane ruffling via the small GTPase Rac. In BHK-21 c...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 1997-04, Vol.272 (16), p.10337-10340
Main Authors: Li, G, D'Souza-Schorey, C, Barbieri, M A, Cooper, J A, Stahl, P D
Format: Article
Language:English
Subjects:
Androstadienes - pharmacology
Animals
Biological Transport
Cell Line
Cell Membrane - physiology
Cell Membrane - ultrastructure
Cloning, Molecular
Cricetinae
Endosomes - metabolism
Endosomes - ultrastructure
GTP-Binding Proteins - metabolism
Horseradish Peroxidase
Pinocytosis
ras Proteins - metabolism
Recombinant Proteins - metabolism
Signal Transduction
Sindbis Virus
Transfection
Wortmannin
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Activation of Ras stimulates cell surface membrane ruffling and pinocytosis. Although seen as coupled events, our study demonstrates that membrane ruffling and pinocytosis are regulated by distinct Ras signal transduction pathways. Ras controls membrane ruffling via the small GTPase Rac. In BHK-21 cells, expression of the constitutively active Rac1(G12V) mutant, via a Sindbis virus vector, resulted in a dramatic stimulation of membrane ruffling without affecting the uptake of horseradish peroxidase. Expression of Ha-Ras(G12V), an activated Ras mutant, stimulated both membrane ruffling and horseradish peroxidase uptake. The Ha-Ras(G12V)-stimulated pinocytosis but not membrane ruffling was abolished by either wortmannin or co-expression with a dominant negative mutant of Rab5, Rab5(S34N). Expression of the activated Rab5(Q79L) mutant mimics the stimulatory effect of Ha-Ras(G12V) on pinocytosis but not membrane ruffling. Our data indicate that Ha-Ras(G12V) separately activates Rab5-dependent pinocytosis and Rac1-dependent membrane ruffling.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.272.16.10337