Platelet-derived growth factor (PDGF)-induced disulfide-linked dimerization of PDGF receptor in living cells.
It is well established that epidermal growth factor and platelet-derived growth factor (PDGF) are able to induce noncovalent dimerization of their surface receptors. It is thought that receptor dimerization plays an important role in activation of the tyrosine kinase function and in the process of receptor autophosphorylation. Here we show that the addition of either PDGF-BB or PDGF-AA to intact 3T3 cells induces formation of 400- and 430-kDa species, respectively, recognized by either anti-PDGF receptor antibodies or anti-phosphotyrosine antibodies. Interestingly, the 400- and the 430-kDa species are detected in nonreducing gels but not in reducing gels. Moreover, an alkylating agent, N-ethylmaleimide, inhibits PDGF-induced formation of high-molecular-mass species. Comparisons of V8 protease peptide maps of [35S]methionine-labeled PDGF receptors and high-molecular-mass proteins indicate that they represent dimers of PDGF receptors. It appears therefore that in addition to noncovalent dimerization, PDGF receptors undergo ligand-dependent disulfide-linked dimerization.
Li
W
W
Department of Pharmacology, New York University Medical Center, New York 10016.
Schlessinger
J
J
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004220:Disulfides / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D066246:ErbB Receptors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D007118:Immunoassay; D046911:Macromolecular Substances; D008715:Methionine / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D010449:Peptide Mapping; D010982:Platelet-Derived Growth Factor / Q000378:metabolism / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D017479:Receptors, Platelet-Derived Growth Factor; D014162:Transfection
D004220:Disulfides; D046911:Macromolecular Substances; D010982:Platelet-Derived Growth Factor; D011956:Receptors, Cell Surface; D008715:Methionine; D066246:ErbB Receptors; D017479:Receptors, Platelet-Derived Growth Factor