Fig. 6.

In MDCK cells the AQP2-L137P mutant has altered ubiquitylation. AQP2 was immunoprecipitated from cell lysates isolated from MDCK cells stably expressing AQP2-WT or AQP2-L137P. Each lane represents a sample from an individual well. Controls included performing the immunoprecipitation with antibody alone (ab), with lysate alone (no ab) or with no lysate or antibody added to the column (only beads). The experiment was repeated twice with similar results. a Immunoblotting of AQP2 demonstrates the higher molecular mass of the AQP2-L137P mutant. b Immunoblotting the same samples for ubiquitin highlights a highly smeared ubiquitylated AQP2 pattern for the mutant