| Although c Cbl is found to be phosphorylated by LTK and therefore is a second candidate linking LTK with the PI 3 kinase pathway along with IRS 1 , we found that the p 85 subunit of PI 3 kinase directly binds to tyrosine 753 of LTK , which is located within a YXXM motif , a consensus binding amino acid sequence for the SH 2 domain of p 85 , but fails to bind to IRS 1 or c Cbl . 0.5241187^^^ |