Depletion of SUMO ligase hMMS21 impairs G1 to S transition in MCF-7 breast cancer cells

► hMMS21-depletion slows MCF-7 breast cancer cell growth. ► hMMS21-depletion impairs G1-S progression. ► hMMS21-depletion lowers E2F1 expression and cyclin E/CDK2 activity. ► hMMS21-depletion increases p21 expression and CDK2-p21 association. ► SUMO ligase activity of hMMS21 is involved.