Fig. 2.

EphrinB1 and ephrinB2 differentially regulate EphB1/B2 and Src activation.

Representative phospho-specific and total protein Western blots of whole cell lysates of D556 native control MB cells (−) or D556 cells transfected with negative control siRNA (NC), ephrinB1 siRNA (+), ephrinB2 siRNA (+), or ephrinB1 cDNA (+), as indicated. GAPDH serves as internal protein loading control in each experiment. a) EphrinB1 knockdown (left panels) results in a modest decrease in the level of EphB1/B2 phosphorylation (forward signaling), but does not alter the level of Src phosphorylation (reverse signaling). EphrinB2 knockdown (right panels) results in a marked decrease in the level of EphB1/B2 and Src phosphorylation. b) EphrinB1 overexpression results in a modest increase in the level of EphB1/B2 phosphorylation, but does not alter the level of Src phosphorylation or total protein expression of EphB1