Figure 5.

Immunolocalization of the Na⁺,K⁺-ATPase, arrestin, and spinophilin in COS cells. COS cells were transfected with flag-arrestin alone (A–C) or with flag-arrestin plus myc-spinophilin (D–I), and cells were stained with anti-flag for arrestin (A, D, and G) and anti-Na⁺,K⁺-ATPase (B and E) or anti-c-myc for spinophilin (H) antibodies. Overlay patterns are shown in C, F, and I (×200 magnification). The Na⁺,K⁺-ATPase is located in intracellular structures when cells express arrestin alone. This effect is not observed when arrestin is expressed together with spinophilin. Arrestin is distributed at least in part at the plasma membrane when spinophilin is coexpressed. Typical results from one of three experiments are shown.