In vitro and in vivo interactions of CIN85/CMS adaptors with the human pTα cytoplasmic tail. (A) Proline-rich motifs within the cytoplasmic domain of human pTα. (B) Domain organization of CMS, CIN85, and CD2BP3 members of the CIN85/CMS adaptor family. (C) CMS and CIN85 interact in vitro with the human pTα cytoplasmic domain. Cell lysates from COS7 cells transfected with Flag-tagged CMS or CIN85 were pulled-down with a GST fusion protein of the pTα tail (GST-pTα) or with GST alone. Immunoblotting was carried out with an anti-Flag mAb. (D) CMS interacts in vivo with the human pTα cytoplasmic domain. Total-cell lysates of SupT1 cells transfected with Flag-tagged CMS or with an empty vector were immunoprecipitated with a rabbit antibody against the human pTα cytoplasmic tail or with preimmune rabbit serum (NRS), and analyzed by Western blotting with anti-Flag. Data are representative of at least 3 independent experiments. Vertical lines have been inserted to indicate a repositioned gel lane.