PKD1 interacts with DVL1 and DVL2, but DVLs do not affect WNT9B-induced PKD1/TRPP2-mediated currents
Next, we tested whether PKD1 could physically interact DVL1 and DVL2 (DVL3 is not present in these cells determined by RT-PCR). We found that DVL1 and DVL2 co-immunoprecipitated with PKD1 in wild type or Pkd2-null MEFs (Fig. 6a and b). Deletion analysis showed that DVL2 interacted with PKD1 and the interaction was abrogated by the E499G mutation in DVL238. This mutation is located within the Dishevelled, Egl-10 and Plecstrin (DEP) domain (Fig. 6c), known to mediate the effects of DVL2 on PCP39, 40. It also impairs phosphorylation of DVL238. Nevertheless, depletion of DVL2 or both DVL1 and DVL2 using RNAi (Fig. 6e) did not show a significant effect on WNT9B-induced whole cell currents (Fig. 6d), suggesting that although DVL1/2 physically interact with PKD1, they are not required for the formation of a functional PKD1/TRPP2 channel complex.