Linked Life Data

11466321

Source:http://linkedlifedata.com/resource/pubmed/id/11466321

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
2001-9-10
pubmed:abstractText
Stimulation of HIRcB fibroblasts with insulin leads to accumulation of active components of the mitogen-activated protein kinase cascade in endocytic compartments. However, the factors that regulate the mobilization of these components through the endocytic pathway and the relevance of this event to cellular signaling remain unclear. Here we report that Ras proteins are associated with lipid rafts in resting HIRcB fibroblasts. Ras is rapidly internalized into the endocytic compartment following stimulation with insulin. The redistribution of Ras is independent of its activation. Attachment of the C-terminal 20 amino acids of Ha-Ras to green fluorescent protein was sufficient to target this construct to the same loci as the endogenous Ras protein, indicating that Ras distribution is a consequence of the association of its lipid modified C terminus with membranes. Depletion of plasma membrane cholesterol delocalized Ras and blocked insulin-dependent Ras traffic. Cholesterol depletion also blocked insulin-dependent phosphorylation of MEK and mitogen-activated protein kinase (MAPK) but had no effects on the translocation and activation of Raf-1. A second inhibitor of endocytosis, cytochalasin D, also blocked insulin-dependent MAPK phosphorylation. Taken together, these results suggest that mobilization of active Raf-1 through the endocytic compartment is required for completion of the MAPK cascade.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
34928-33
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Agonist-dependent traffic of raft-associated Ras and Raf-1 is required for activation of the mitogen-activated protein kinase cascade.
pubmed:affiliation
Department of Pharmacology and Cell Biology and Physiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't