PDGF, receptor

Among the substrates of Src are other nonreceptor PTKs (e.g., Fak, Syk, and Tec kinases), RTKs (e.g. EGF and PDGF receptors), phospholipase Cy, PI3-kinase, phosphatases (e.g., SHP-2 and PP2A), and adaptor (e.g., She and Cbl) as well as focal adhesion proteins (e.g., paxillin, pl30Cas andtensin). Src-mediated phosphorylation either modulates enzymatic activity of... 

All RTKs contain between one and three tyrosines in the kinase activation loop, which is composed of subdomains VII and VIII of the protein kinase catalytic core. Phosphorylation of these tyrosines has been shown to be critical for stimulation of catalytic activity and biological function for a number of RTKs, including insulin receptor, FGF receptor, VEGF receptor, PDGF receptor, Met (hepatocyte growth factor receptor), and TrkA (NGF receptor). A major exception is the EGF receptor, for which autophosphorylation of a conserved tyrosine in the activation loop does not seem to be involved in signaling. Substitution of tyrosine with phenylalanine has no effect on RTK activity or downstream signals. 

Normal skin appears to be devoid of PDGF receptors. Animal studies illustrate that rapid expression of both a and P receptor subunits is induced upon generation of an experimental wound (e.g. a surgical incision). Receptor expression is again switched off following re-epithelialization and complete healing of the wound. 

Ohvera, A., Edsall, L., Poulton, S., Kazlauskas, A. and Spiegel, S., 1999, Platelet-derived growth factor-induced activation of sphingosine kinase requires phosphorylation of the PDGF receptor tyrosine residue responsible for binding of PLCy, FASEB J. 13 1593-1600. 

Levitzki A. PDGF receptor kinase inhibitors for the treatment of PDGF driven diseases. Cytokine Growth Factor Rev 2004 15 229-35. 

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