scholarly journals Requirement for Phosphatidylinositol 3′-Kinase Activity in Platelet-derived Growth Factor-stimulated Tyrosine Phosphorylation of p125 Focal Adhesion Kinase and Paxillin

1996 ◽  
Vol 271 (13) ◽  
pp. 7829-7834 ◽  
Author(s):  
Sara Rankin ◽  
Roya Hooshmand-Rad ◽  
Lena Claesson-Welsh ◽  
Enrique Rozengurt
Keyword(s):  
Growth Factor ◽  
Focal Adhesion Kinase ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Kinase Activity ◽  
Platelet Derived Growth Factor ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatidylinositol 3

scholarly journals Tyrosine mutations within the alpha platelet-derived growth factor receptor kinase insert domain abrogate receptor-associated phosphatidylinositol-3 kinase activity without affecting mitogenic or chemotactic signal transduction.

1991 ◽  
Vol 11 (7) ◽  
pp. 3780-3785 ◽  
Author(s):  
J C Yu ◽  
M A Heidaran ◽  
J H Pierce ◽  
J S Gutkind ◽  
D Lombardi ◽  
...  
Keyword(s):  
Growth Factor ◽  
Kinase Activity ◽  
Growth Factor Receptor ◽  
Platelet Derived Growth Factor ◽  
Pdgf Receptor ◽  
Tyrosine Residue ◽  
Phosphatidylinositol 3 Kinase ◽  
Ligand Stimulation ◽  
Phosphatidylinositol 3

A phosphatidylinositol-3 (PI-3) kinase activity of unknown biological function associates with tyrosine kinase-containing proteins, including a number of growth factor receptors after ligand stimulation. In the beta platelet-derived growth factor (beta PDGF) receptor, phosphorylation of a specific tyrosine residue within the kinase insert domain was required for its interaction with this enzyme. We show that substitutions of phenylalanine for tyrosine residue 731 or 742 within the kinase insert domain of the alpha PDGF receptor do not impair PDGF-induced tyrosine phosphorylation of the receptor or of an in vivo substrate, phospholipase C-gamma. Moreover, phosphatidylinositol turnover in response to ligand stimulation is unaffected. However, both lesions markedly impair receptor association with PI-3 kinase. Antiphosphotyrosine antibody-recoverable PI-3 kinase was also dramatically reduced in PDGF-stimulated cells expressing either mutant receptor. Since neither mutation abolished PDGF-induced mitogenesis or chemotaxis, we conclude that alpha PDGF receptor-associated PI-3 kinase activity is not required for either of these major PDGF signalling functions.

scholarly journals A phosphatidylinositol-3 kinase binds to platelet-derived growth factor receptors through a specific receptor sequence containing phosphotyrosine.

1991 ◽  
Vol 11 (2) ◽  
pp. 1125-1132 ◽  
Author(s):  
J A Escobedo ◽  
D R Kaplan ◽  
W M Kavanaugh ◽  
C W Turck ◽  
L T Williams
Keyword(s):  
Growth Factor ◽  
Kinase Activity ◽  
Pi3 Kinase ◽  
Platelet Derived Growth Factor ◽  
Pdgf Receptor ◽  
Phosphatidylinositol 3 Kinase ◽  
Cell Lysates ◽  
Phosphorylated Peptides ◽  
Insert Region ◽  
Phosphatidylinositol 3

Platelet-derived growth factor (PDGF) stimulates autophosphorylation of the PDGF receptor and association of the receptor with several cytoplasmic molecules, including phosphatidylinositol-3 kinase (PI3 kinase). In this study we examined the association of PI3 kinase with immunoprecipitated autophosphorylated PDGF receptor in vitro. The PI3 kinase from cell lysates bound to the wild-type receptor but not to a mutant receptor that had a deletion of the kinase insert region. A protein of an apparent size of 85 kDa bound to the receptor, consistent with previous observations that a protein of this size is associated with PI3 kinase activity. In addition, 110- and 74-kDa proteins bound to the phosphorylated receptor. Dephosphorylated receptors lost the ability to bind PI3 kinase activity as well as the 85-kDa protein. A 20-amino-acid peptide composed of a sequence in the kinase insert region that included one of the autophosphorylation sites of the receptor (tyrosine 719) as well as a nearby tyrosine (Y708) blocked the binding of PI3 kinase to the receptor, but only when the peptide was phosphorylated on tyrosine residues. A scrambled version of the peptide did not block PI3 kinase binding to the receptor even when it was phosphorylated on tyrosine. These tyrosine-phosphorylated peptides did not block binding of phospholipase C-gamma or GTPase-activating protein to the receptor. In separate experiments (receptor blots), soluble radiolabeled receptor bound specifically to an 85-kDa protein present in sodium dodecyl sulfate-polyacrylamide gel electrophoresis-fractionated 3T3 cell lysates that were transferred to nitrocellulose paper. The binding was blocked by the same tyrosine-phosphorylated peptides that prevented binding of PI3 kinase activity to immobilized receptors. These findings show that the PDGF receptor binds directly to an 85-kDa protein and to a PI3 kinase activity through specific sequences in the kinase insert region. The association of a 110-kDa protein with the receptor also involve these sequences, suggesting that this protein may be a subunit of the PI3 kinase. Phosphotyrosine is an essential structure required for the interactions of these proteins with the PDGF receptor.

Tyrosine mutations within the alpha platelet-derived growth factor receptor kinase insert domain abrogate receptor-associated phosphatidylinositol-3 kinase activity without affecting mitogenic or chemotactic signal transduction

1991 ◽  
Vol 11 (7) ◽  
pp. 3780-3785
Author(s):  
J C Yu ◽  
M A Heidaran ◽  
J H Pierce ◽  
J S Gutkind ◽  
D Lombardi ◽  
...  
Keyword(s):  
Growth Factor ◽  
Kinase Activity ◽  
Growth Factor Receptor ◽  
Platelet Derived Growth Factor ◽  
Pdgf Receptor ◽  
Tyrosine Residue ◽  
Phosphatidylinositol 3 Kinase ◽  
Ligand Stimulation ◽  
Phosphatidylinositol 3

A phosphatidylinositol-3 (PI-3) kinase activity of unknown biological function associates with tyrosine kinase-containing proteins, including a number of growth factor receptors after ligand stimulation. In the beta platelet-derived growth factor (beta PDGF) receptor, phosphorylation of a specific tyrosine residue within the kinase insert domain was required for its interaction with this enzyme. We show that substitutions of phenylalanine for tyrosine residue 731 or 742 within the kinase insert domain of the alpha PDGF receptor do not impair PDGF-induced tyrosine phosphorylation of the receptor or of an in vivo substrate, phospholipase C-gamma. Moreover, phosphatidylinositol turnover in response to ligand stimulation is unaffected. However, both lesions markedly impair receptor association with PI-3 kinase. Antiphosphotyrosine antibody-recoverable PI-3 kinase was also dramatically reduced in PDGF-stimulated cells expressing either mutant receptor. Since neither mutation abolished PDGF-induced mitogenesis or chemotaxis, we conclude that alpha PDGF receptor-associated PI-3 kinase activity is not required for either of these major PDGF signalling functions.

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