Regulation of G1/S progression by SCML2.

<p>(A) Western blot analysis of nuclear extracts isolated from U2OS cells transfected with siRNA against either SCML2 (#2) or p21 (si p21) or a control siRNA (si C). Cells were collected every 2 h, as indicated, after release from a mitotic arrest induced with nocodazole. The extracts were analyzed using antibodies specific to USP7 (loading control), SCML2, CYCE2, CYCB2, CDK2, p27, and p21. (B) Densitometric analysis of the levels of p21 at different points after release from mitosis in cells treated with a control siRNA or specific for SCML2 (si #2). The expression was normalized to the levels of CDK2, and the mean of four different experiments is shown. (C) Western blot analysis of nuclear extracts isolated from U2OS cells transfected with a control siRNA and plasmid (Control), with an siRNA against SCML2 and a control plasmid (si #2) or an siRNA against SCML2 and a plasmid expressing SCML2B resistant to the siRNA (si #2+SCML2B). Cells were collected every 2 h, as indicated, after release from a mitotic arrest induced with nocodazole. The extracts were analyzed using antibodies specific to p21. Ponceau staining is shown as loading control. (D) Densitometric analysis of the levels of p21 at different time points after release from mitosis in two independent experiments.