Fig. 6. The CAR interaction with MAGI-1b, PICK1 and PSD-95 depends on the CAR PDZ-binding motif GSIV. (A) shows the immunofluorescent staining of COS-7 cells expressing CAR, CAR^GSIV, MAGI-1b-GFP, PICK1-GFP, or PSD-95-GFP alone. CAR and CAR^GSIV primarily localize to the junctions between cells while MAGI-1b-GFP, PICK1-GFP, and PSD-95-GFP show mainly diffuse staining. (B) shows significant colocalization (yellow) of MAGI-1b-GFP, PICK1-GFP or PSD-95-GFP with CAR (red in merged images) upon co-transfection. By contrast, there was no alteration in staining and no significant colocalization between these proteins when co-expressed with CAR^GSIV (red in merged images).