Fig. 6. The I630E mutation in Rip11 blocks Rab11a and Rab11b binding. (A) CHO.T cells were transfected with plasmids encoding GFP-tagged Rab11a or GFP-vector, along with plasmids encoding either Xpress-tagged wild-type Rip11 (Rip11-WT) or Rip11-I630E, as indicated. The cells were incubated in the absence or presence of 100 nM insulin for 10 minutes, as shown, before lysis. Cell lysates were blotted with antibodies against GFP (lysate: IB Rab11a) or antibodies against Xpress (lysate: IB Rip11) to assess the level of expression of these proteins. Alternatively, Rab11a was immunoprecipitated using antibody against GFP, and the complexes were blotted with antibody against Xpress (IP Rab11a: IB Rip11) or against GFP (IP Rab11a: IB Rab11a) to detect the presence of Xpress-tagged Rip11 and GFP-tagged Rab11a in the precipitates, respectively. (B) A similar experiment to panel A was performed, except that the Rab11a expression plasmid was replaced with an equivalent plasmid expressing Rab11b.