The small GTPase R-Ras regulates organization of actin and drives membrane protrusions through the activity of PLCε

Aude S. Ada-Nguema, Harry Xenias, Michael Sheetz, Patricia J. Keely

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

R-Ras, an atypical member of the Ras subfamily of small GTPases, enhances integrin-mediated adhesion and signaling through a poorly understood mechanism. Dynamic analysis of cell spreading by total internal reflection fluorescence (TIRF) microscopy demonstrated that active R-Ras lengthened the duration of initial membrane protrusion, and promoted the formation of a ruffling lamellipod, rich in branched actin structures and devoid of filopodia. By contrast, dominant-negative R-Ras enhanced filopodia formation. Moreover, RNA interference (RNAi) approaches demonstrated that endogenous R-Ras contributed to cell spreading. These observations suggest that R-Ras regulates membrane protrusions through organization of the actin cytoskeleton. Our results suggest that phospholipase Cε (PLCε) is a novel R-Ras effector mediating the effects of R-Ras on the actin cytoskeleton and membrane protrusion, because R-Ras was co-precipitated with PLCε and increased its activity. Knockdown of PLCε with siRNA reduced the formation of the ruffling lamellipod in R-Ras cells. Consistent with this pathway, inhibitors of PLC activity, or chelating intracellular Ca2+ abolished the ability of R-Ras to promote membrane protrusions and spreading. Overall, these data suggest that R-Ras signaling regulates the organization of the actin cytoskeleton to sustain membrane protrusion through the activity of PLCε.

Original languageEnglish (US)
Pages (from-to)1307-1319
Number of pages13
JournalJournal of Cell Science
Volume119
Issue number7
DOIs
StatePublished - Apr 1 2006
Externally publishedYes

Fingerprint

Monomeric GTP-Binding Proteins
Type C Phospholipases
Actins
Actin Cytoskeleton
Membranes
Pseudopodia
RNA Interference
Fluorescence Microscopy
Integrins
Small Interfering RNA

Keywords

  • Actin
  • Ca
  • Cell adhesion
  • Cell spreading
  • Integrin
  • PLC
  • R-Ras

ASJC Scopus subject areas

  • Cell Biology

Cite this

The small GTPase R-Ras regulates organization of actin and drives membrane protrusions through the activity of PLCε. / Ada-Nguema, Aude S.; Xenias, Harry; Sheetz, Michael; Keely, Patricia J.

In: Journal of Cell Science, Vol. 119, No. 7, 01.04.2006, p. 1307-1319.

Research output: Contribution to journalArticle

Ada-Nguema, Aude S. ; Xenias, Harry ; Sheetz, Michael ; Keely, Patricia J. / The small GTPase R-Ras regulates organization of actin and drives membrane protrusions through the activity of PLCε. In: Journal of Cell Science. 2006 ; Vol. 119, No. 7. pp. 1307-1319.
@article{84b1c198d67c462cb368d381b7e60453,
title = "The small GTPase R-Ras regulates organization of actin and drives membrane protrusions through the activity of PLCε",
abstract = "R-Ras, an atypical member of the Ras subfamily of small GTPases, enhances integrin-mediated adhesion and signaling through a poorly understood mechanism. Dynamic analysis of cell spreading by total internal reflection fluorescence (TIRF) microscopy demonstrated that active R-Ras lengthened the duration of initial membrane protrusion, and promoted the formation of a ruffling lamellipod, rich in branched actin structures and devoid of filopodia. By contrast, dominant-negative R-Ras enhanced filopodia formation. Moreover, RNA interference (RNAi) approaches demonstrated that endogenous R-Ras contributed to cell spreading. These observations suggest that R-Ras regulates membrane protrusions through organization of the actin cytoskeleton. Our results suggest that phospholipase Cε (PLCε) is a novel R-Ras effector mediating the effects of R-Ras on the actin cytoskeleton and membrane protrusion, because R-Ras was co-precipitated with PLCε and increased its activity. Knockdown of PLCε with siRNA reduced the formation of the ruffling lamellipod in R-Ras cells. Consistent with this pathway, inhibitors of PLC activity, or chelating intracellular Ca2+ abolished the ability of R-Ras to promote membrane protrusions and spreading. Overall, these data suggest that R-Ras signaling regulates the organization of the actin cytoskeleton to sustain membrane protrusion through the activity of PLCε.",
keywords = "Actin, Ca, Cell adhesion, Cell spreading, Integrin, PLC, R-Ras",
author = "Ada-Nguema, {Aude S.} and Harry Xenias and Michael Sheetz and Keely, {Patricia J.}",
year = "2006",
month = "4",
day = "1",
doi = "10.1242/jcs.02835",
language = "English (US)",
volume = "119",
pages = "1307--1319",
journal = "Journal of Cell Science",
issn = "0021-9533",
publisher = "Company of Biologists Ltd",
number = "7",

}

TY - JOUR

T1 - The small GTPase R-Ras regulates organization of actin and drives membrane protrusions through the activity of PLCε

AU - Ada-Nguema, Aude S.

AU - Xenias, Harry

AU - Sheetz, Michael

AU - Keely, Patricia J.

PY - 2006/4/1

Y1 - 2006/4/1

N2 - R-Ras, an atypical member of the Ras subfamily of small GTPases, enhances integrin-mediated adhesion and signaling through a poorly understood mechanism. Dynamic analysis of cell spreading by total internal reflection fluorescence (TIRF) microscopy demonstrated that active R-Ras lengthened the duration of initial membrane protrusion, and promoted the formation of a ruffling lamellipod, rich in branched actin structures and devoid of filopodia. By contrast, dominant-negative R-Ras enhanced filopodia formation. Moreover, RNA interference (RNAi) approaches demonstrated that endogenous R-Ras contributed to cell spreading. These observations suggest that R-Ras regulates membrane protrusions through organization of the actin cytoskeleton. Our results suggest that phospholipase Cε (PLCε) is a novel R-Ras effector mediating the effects of R-Ras on the actin cytoskeleton and membrane protrusion, because R-Ras was co-precipitated with PLCε and increased its activity. Knockdown of PLCε with siRNA reduced the formation of the ruffling lamellipod in R-Ras cells. Consistent with this pathway, inhibitors of PLC activity, or chelating intracellular Ca2+ abolished the ability of R-Ras to promote membrane protrusions and spreading. Overall, these data suggest that R-Ras signaling regulates the organization of the actin cytoskeleton to sustain membrane protrusion through the activity of PLCε.

AB - R-Ras, an atypical member of the Ras subfamily of small GTPases, enhances integrin-mediated adhesion and signaling through a poorly understood mechanism. Dynamic analysis of cell spreading by total internal reflection fluorescence (TIRF) microscopy demonstrated that active R-Ras lengthened the duration of initial membrane protrusion, and promoted the formation of a ruffling lamellipod, rich in branched actin structures and devoid of filopodia. By contrast, dominant-negative R-Ras enhanced filopodia formation. Moreover, RNA interference (RNAi) approaches demonstrated that endogenous R-Ras contributed to cell spreading. These observations suggest that R-Ras regulates membrane protrusions through organization of the actin cytoskeleton. Our results suggest that phospholipase Cε (PLCε) is a novel R-Ras effector mediating the effects of R-Ras on the actin cytoskeleton and membrane protrusion, because R-Ras was co-precipitated with PLCε and increased its activity. Knockdown of PLCε with siRNA reduced the formation of the ruffling lamellipod in R-Ras cells. Consistent with this pathway, inhibitors of PLC activity, or chelating intracellular Ca2+ abolished the ability of R-Ras to promote membrane protrusions and spreading. Overall, these data suggest that R-Ras signaling regulates the organization of the actin cytoskeleton to sustain membrane protrusion through the activity of PLCε.

KW - Actin

KW - Ca

KW - Cell adhesion

KW - Cell spreading

KW - Integrin

KW - PLC

KW - R-Ras

UR - http://www.scopus.com/inward/record.url?scp=33646806089&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33646806089&partnerID=8YFLogxK

U2 - 10.1242/jcs.02835

DO - 10.1242/jcs.02835

M3 - Article

C2 - 16537651

AN - SCOPUS:33646806089

VL - 119

SP - 1307

EP - 1319

JO - Journal of Cell Science

JF - Journal of Cell Science

SN - 0021-9533

IS - 7

ER -