Figure 3.

Immunoprecipitation of polycystin synthesized in vitro. (Upper) Schematic of fusion proteins for generation of domain specific polyclonal antibodies. Each fusion protein consists of the carrier glutathione S-transferase (GST) or maltose binding protein (MBP) and the indicated region of polycystin. (Lower) For immunoprecipitation, in vitro translated products from SrfI delta (N-terminal half of the PKD1 protein), and BRASH 7 (C-terminal half of the PKD1 protein), were used. Antibodies were coupled to protein A Sepharose. Both the bound (b) and void (v) protein fractions were analyzed for each immunoprecipitation. Immunoprecipitation of luciferase was performed as a negative control.