Platelet-derived growth factor receptor sequences important for binding of src family tyrosine kinases.

We previously demonstrated that src family tyrosine kinases associate with activated platelet-derived growth factor receptors. We have now investigated the requirement for tyrosine phosphorylation sites in the human platelet-derived growth factor receptor for this binding. Tyrosine 857, but not tyrosine 751, is required for efficient association. Furthermore, even though src family tyrosine kinases associate with receptors lacking tyrosine 751, they are not activated, implying that association does not invariably lead to activation.