Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2007-3-23
pubmed:abstractText
Cancer cells depend on chemotaxis for invasion and frequently overexpress and/or activate Src. We previously reported that v-Src accelerates motility by promoting phosphoinositide 3-kinase (PI3-K) signalling but abrogates chemotaxis. We here addressed the mechanism of the loss of chemotactic response to platelet-derived growth factor (PDGF) gradients in fibroblasts harbouring a thermosensitive v-Src kinase. At non-permissive temperature, PDGF receptor (PDGFR) signalling, assessed by phosphoY(751)-specific antibodies (a docking site for PI3-K), was not detected without PDGF and showed a concentration-dependent PDGF response. Both immunolabeling of PI3-K (p110) and live cell imaging of its product (phosphatidylinositol 3,4,5 tris-phosphate) showed PI3-K recruitment and activation at lamellipodia polarized towards a PDGF gradient. Centrosomes and PDGFR- and Src-bearing endosomes were also oriented towards this gradient. Upon v-Src thermoactivation, (i) Y(751) phosphorylation was moderately induced without PDGF and synergistically increased with PDGF; (ii) PI3-K was recruited and activated all along the plasma membrane without PDGF and did not polarize in response to a PDGF gradient; and (iii) polarization of centrosomes and of PDGFR-bearing endosomes were also abrogated. Thus, PDGF can further increase PDGFR auto-phosphorylation despite strong Src kinase activity, but diffuse downstream activation of PI3-K by Src abrogates cell polarization and chemotaxis: "signalling requires silence".
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-4827
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
313
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1090-105
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:17335807-Animals, pubmed-meshheading:17335807-Cell Line, pubmed-meshheading:17335807-Cell Membrane, pubmed-meshheading:17335807-Centrosome, pubmed-meshheading:17335807-Chemotaxis, pubmed-meshheading:17335807-Cytoplasm, pubmed-meshheading:17335807-Cytoskeleton, pubmed-meshheading:17335807-Enzyme Activation, pubmed-meshheading:17335807-Fibroblasts, pubmed-meshheading:17335807-Focal Adhesions, pubmed-meshheading:17335807-Microtubule-Organizing Center, pubmed-meshheading:17335807-Oncogene Protein pp60(v-src), pubmed-meshheading:17335807-Phosphatidylinositol 3-Kinases, pubmed-meshheading:17335807-Platelet-Derived Growth Factor, pubmed-meshheading:17335807-Proto-Oncogene Proteins c-akt, pubmed-meshheading:17335807-Rats, pubmed-meshheading:17335807-Receptors, Platelet-Derived Growth Factor, pubmed-meshheading:17335807-Signal Transduction
pubmed:year
2007
pubmed:articleTitle
Constitutive diffuse activation of phosphoinositide 3-kinase at the plasma membrane by v-Src suppresses the chemotactic response to PDGF by abrogating the polarity of PDGF receptor signalling.
pubmed:affiliation
Université catholique de Louvain, Christian de Duve Institute of Cellular Pathology, CELL Unit, UCL 75.41, avenue Hippocrate, 75, B-1200 Brussels, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't