Differential effects of base-specific chaperones on proteasome assembly with Walker A mutant Rpts.
A–D, immunoblotting analysis of FLAG-Rpt samples following coexpression of base-specific chaperones. HeLa cells expressing wild-type or Walker A mutant FLAG-Rpt1 (A), Rpt6 (B), Rpt3 (C), and Rpt5 (D) were transfected with the expression constructs of HA-tagged S5b, PAAF1, Gankyrin, and p27, respectively. After affinity purification of FLAG-tagged proteins in the presence of 5 mm ATP, the samples were analyzed by immunoblotting with indicated antibodies.