Figure 1. Absence of Vav or Slp76 abolishes downstream ERK1/2 phosphorylation in response to IFNα in Jurkat cells.

Protein lysates were obtained from (a) Jurkat cells, Vav-deficient J.Vav1 cells and J.Vav1 cells reconstituted with a Vav-expressing construct, (b) Jurkat cells, Slp76-deficient J14 cells and J14 cells reconstituted with Slp76–RFP or (c) Slp76-deficient J14 cells and J14 cells reconstituted with the Slp76-Y3F–RFP mutant. Cells were stimulated with IFNα over the time course indicated. Western blotting was used to determine the expression levels of phospho(Thr²⁰²/Tyr²⁰⁴)-ERK1/2, ERK1/2 and to determine Vav and Slp76 expression levels, to ensure the presence or absence of each protein in the respective cell lines. β-Actin was used as a loading control.