FIG 2.

SIRT5 protein levels are increased/stabilized in the absence of cyclin F. (A) Immunoblot for sirtuin proteins in cyclin F crWT and crKO HeLa cells shows modest increases in SIRT5 and SIRT7 protein levels. (B and C) Cyclin F siRNA-mediated knockdown using 2 independent siRNAs in U2OS (B) and 293T (C) show increased SIRT5 protein levels, as well as other reported cyclin F substrates CP110 and Cdh1. (D) SIRT5 protein half-life in cyclin F crWT and crKO HeLa cells was measured using a cycloheximide (CHX) assay. Cells were treated with CHX, and samples were taken at the indicated time points.