Fig. 6. RGS19 attenuates Wnt–-catenin signaling upstream of Dvl. (A) F9 cells transiently transfected with vectors encoding Fz1 and RGS19 were treated with or without Wnt3a for the indicated lengths of time. Lysates were collected and separated by SDS-PAGE on a 10% acrylamide gel, transferred to nitrocellulose and probed with an antibody against Dvl3. The increase in phosphorylated Dvl3 (P-Dvl3) that is seen in response to Wnt3a can be attenuated by overexpression of RGS19. (B) F9 cells transiently transfected with vectors encoding Fz1 and RGS19 were treated with or without Wnt3a for the indicated lengths of time. Lysates were collected, treated with alkaline phosphatase for 1 hour, separated by SDS-PAGE on a 10% acrylamide gel, transferred to nitrocellulose and probed with an antibody against Dvl3. The absence of the slowest migrating band indicates that this band is a phosphorylated isoform of Dvl3. Min, minutes. (C) F9 cells transiently transfected with vectors encoding Fz1 and Dvl3 or RGS19 were collected and subjected to the luciferase assay. The increase in gene transcription stimulated by Dvl3 cannot be attenuated by RGS19. The results displayed are from a single experiment representative of more than three independent tests. The data shown in C are mean values (±s.e.) of at least three separate experiments. *P<0.05 for the difference between wild-type cells and those expressing Dvl3 or Dvl3 and RGS19.