Figure 5.

Activation of mitotic and interphase APC by purified phosphorylated CDC20 and CDH1. (A) CDC20 and CDH1 were purified from baculovirus-infected Sf9 cells that had been treated (CDC20^OA and CDH1^OA) or not treated (CDC20 and CDH1) with OA and analyzed by SDS-PAGE and Coomassie staining. (B and C) Different amounts of the purified proteins were tested for their ability to stimulate the cyclin B ubiquitination activity of interphase APC (APCⁱ; B) or mitotic APC (APC^m; C) purified from Xenopus eggs. The ubiquitination assays were analyzed as described in Figure 4.