Figure 2.

FBXL2 targets cyclin D2 for ubiquitination during mitosis. (A) MLE cells were synchronized to each cell phase followed by coimmunoprecipitation of endogenous FBXL2 and then cyclin D2 immunoblotting. (B) Cells were immunostained for cyclin D2 and counterstained with DAPI to visualize nucleus. (C) In vivo ubiquitination assays. Polyubiquitinated cyclin D2 was detected during cell-cycle progression by immunoprecipitation of endogenous cyclins followed by immunoblotting for ubiquitin. The arrows show polyubiquitinated cyclin D2. (D) Cyclin D2 levels in cells treated with leupeptin or MG132. The data from each panel represent at n = 2 separate experiments.