Fig 8.
Calreticulin interacts with α4 and Tacδ via the GFFKR motif. (A) Comparison of total CRT expression in lysates of JB4-α4, JB4-α4δ, JB4, JB4-Tacδ, and JB4-Tacδscr cells by Western blotting. Equal protein loading was assessed by immunoblotting for GAPDH. (B) Affinity chromatography using matrix-immobilized GST-KLGFFKR and GST-KLRFGFK (scrambled) recombinant proteins incubated with Jurkat cell lysates. Binding of CRT was assessed by Western blotting. Loading of the GST recombinant proteins was visualized by Coomassie blue staining. (C) Lysates prepared from JB4-α4, JB4-α4δ, and JB4 cells were immunoprecipitated (IP) with an α4 surface epitope antibody or IgG control, and associated proteins were detected with antibodies against CRT and α4. (D) Lysates prepared from JB4-Tacδ and JB4-Tacδscr cells were immunoprecipitated with a Tac surface epitope antibody, and associated proteins were detected with antibodies against CRT and Tac. (E) Lysates prepared from Jurkat cells were plated on the indicated substrates for 45 min and then immunoprecipitated with an α4 surface epitope antibody; associated proteins were detected by blotting with antibodies against CRT and α4.