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Platelet‐derived growth factor‐induced activation of sphingosine kinase requires phosphorylation of the PDGF receptor tyrosine residue responsible for binding of PLCγ
Author(s) -
Olivera Ana,
Edsall Lisa,
Poulton Samantha,
Kazlauskas Andrius,
Spiegel Sarah
Publication year - 1999
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.13.12.1593
Subject(s) - platelet derived growth factor receptor , sphingosine , receptor tyrosine kinase , tyrosine kinase , biology , proto oncogene tyrosine protein kinase src , microbiology and biotechnology , cyclin dependent kinase 9 , mitogen activated protein kinase kinase , biochemistry , chemistry , signal transduction , kinase , protein kinase a , receptor , growth factor
Sphingosine‐1‐phosphate, a sphingo‐lipid metabolite, is involved in the mitogenic response of platelet‐derived growth factor (PDGF) and is formed by activation of sphingosine kinase. We examined the effect of PDGF on sphingosine kinase activation in TRMP cells expressing wild‐type or various mutant βPDGF receptors. Sphingosine ki‐nase was stimulated by PDGF in cells expressing wild‐type receptors but not in cells expressing kinase‐inactive receptors (R634). Cells expressing mutated PDGF receptors with phenylalanine substitutions at five major tyrosine phosphorylation sites 740/751/771/1009/1021 (F5 mutants), which are unable to associate with PLCγ, phosphatidylinositol 3‐kinase, Ras GTPase‐activating protein, or protein tyrosine phosphatase SHP‐2, not only failed to increase DNA synthesis in response to PDGF but also did not activate sphingosine kinase. Moreover, mutation of tyrosine‐1021 of the PDGF receptor to phenylala‐nine, which impairs its association with PLCγ, abrogated PDGF‐induced activation of sphingosine ki‐nase. In contrast, PDGF was still able to stimulate sphingosine kinase in cells expressing the PDGF receptor mutated at tyrosines 740/751 and 1009, responsible for binding of phosphatidylinositol 3‐ki‐nase and SHP‐2, respectively. In agreement, PDGF did not stimulate sphingosine kinase activity in F5 receptor ‘add‐back’ mutants in which association with the Ras GTPase‐activating protein, phosphati‐dylinositol 3‐kinase, or SHP‐2 was individually restored. However, a mutant PDGF receptor that was able to bind PLCγ (tyrosine‐1021), but not other signaling proteins, restored sphingosine kinase sensitivity to PDGF. These data indicate that the ty‐rosine residue responsible for binding of PLCγ is required for PDGF‐induced activation of sphin‐gosine kinase. Moreover, calcium mobilization downstream of PLCγ, but not protein kinase C activation, appears to be required for stimulation of sphin‐gosine kinase by PDGF.—Olivera, A., Edsall, J., Poulton, S., Kazlauskas, A., Spiegel, S. Platelet‐derived growth factor‐induced activation of sphin‐gosine kinase requires phosphorylation of the PDGF receptor tyrosine residue responsible for binding of PLCγ. FASEB J . 13, 1593–1600 (1999)