14-3-3ζ specifically binds the HSRSLP motif of the β_c cytoplasmic domain. (A) HEK 293 cells were used either untransfected (UT) or transfected with wild-type β_c (wt), with β_c containing the sequence⁵⁸¹PHSRSLP⁵⁸⁷ mutated to⁵⁸¹GEFAAAA⁵⁸⁷, or with β_ccontaining the sequence ⁸²⁰RSKPSSP⁸²⁶ mutated to ⁸²⁰EFAAAAA⁸²⁶. Lysates were made and immunoprecipitations were performed using GST–14-3-3-sepharose. The presence of β_c was determined by Western blotting with an anti-β_c antibody (MoAb 1C1). (B) The level of expression β_c in the lysates was determined by Western blotting with an anti-β_c antibody (MoAb 1C1).