Although pY 594 in the EphB1R has previously been shown to bind the SH 2 domain of Nck , we found that stimulation of EphB 1 and EphB 2 led predominantly to a complex between NIK / Nck , p 62 ( dok ) , RasGAP , and an unidentified 145 kDa tyrosine phosphorylated protein . ^^^ Tyrosine phosphorylated p 62 ( dok ) most probably binds directly to the SH 2 domain of Nck and RasGAP and indirectly to NIK bound to the SH 3 domain of Nck . ^^^