| Tyrosine 1213 of Flt 1 is a major binding site of Nck and SHP 2 . ^^^ We examined the interactions of certain proteins with a SH 2 domain with Flt 1 and KDR using the yeast two hybrid system and found that Nck , SHP 2 , PLC gamma , and PI3K p 85 bind to Flt 1 . ^^^ Nck , SHP 2 , and PI3K bind to Y 1213 of Flt 1 . ^^^ Nck also binds to Y 1333 of Flt 1 . ^^^ These results suggest that Nck , SHP 2 , PLC gamma , and PI3K play important roles in Flt 1 signal transduction and that Y 1213 of Flt 1 is a major binding site of PI3K , Nck , and SHP 2 . . ^^^ |