Fig. 5.

MOR deletion mutant I35 is located in the nonraft domains. (A) Relative receptor level in the sucrose gradient fractions. HEK293 cells stably expressing MORI35 was processed, as described in Materials and Methods. The sucrose gradient distribution of I35 was compared with that of WT MOR. (B) Coimmunoprecipitation of I35 and Gαi2. HA and Gαi2 antibodies were used to coimmunoprecipitate Gαi2 and I35. The amount of MOR mutant and Gαi2 coimmunoprecipitated was compared with that of WT MOR. (C) Ability of I35 to mediate ERK1/2 phosphorylation. HEK293 cells with I35 were exposed to 1 μM morphine and 10 nM etorphine for 10 min. The amount of ERK1/2 phosphorylated was determined, as described in Materials and Methods.