Fig. 3.

CTSS increases ubiquitin-mediated degradation of BRCA1. a Western blot analysis in control or si-CTSS transfected MCF7 cells treated with 100 μg/ml cycloheximide (CHX) for various lengths of time. b MCF7 cells were transfected with WT-BRCA1 or BRCT deletion mutant of BRCA1 (ΔBRCT) and incubated in the presence of CHX, and Western blotting was performed. Band density was expressed as the fold change relative to the control (Mean ± SD of 3 experiments). c, d For ubiquitination assays, MCF7 cells were transfected with control, WT-CTSS, C25A-CTSS, sh-CTSS, or BRCA1 constructs after transfection with ubiqutine construct (Ub). Cell lysates were immunoprecipitated (IP) and immunoblotted (IB)