| Tyrosine 740 phosphorylation of discoidin domain receptor 2 by Src stimulates intramolecular autophosphorylation and Shc signaling complex formation . ^^^ DDR 2 mediated cellular signaling has been shown to require Src activity . ^^^ However , the precise mechanism underlying the Src dependence of DDR 2 signaling is unknown . ^^^ Here , using baculoviral co expression of the DDR 2 cytosolic domain and Src , we show that Src targets three tyrosine residues ( Tyr 736 , Tyr 740 , and Tyr 741 ) in the activation loop of DDR 2 for phosphorylation . ^^^ This phosphorylation by Src stimulates DDR 2 cis autophosphorylation of additional tyrosine residues . ^^^ |