YKL-5-124 is a potent, selective, irreversible and covalent CDK7 inhibitor with IC50s of 53.5 nM and 9.7 nM for CDK7 and CDK7/Mat1/CycH, respectively. YKL-5-124 is >100-fold greater selective for CDK7 than CDK9 and CDK2, and inactive against CDK12 and CDK13. YKL-5-124 induces a strong cell-cycle arrest, inhibits E2F-driven gene expression, and exhibits little effect on RNA polymerase II phosphorylation status[1].
YKL-5-124 (0-2000 nM; 72 hours; HAP1 cells) treatment causes a dose-dependent increase in G1- and G2/M-phase cells and a corresponding loss of S-phase cells[1].YKL-5-124 (0-2000 nM; 24 hours; HAP1 WT cells) treatment inhibits CDK1 T-loop phosphorylation, and to a lesser extent CDK2 T-loop phosphorylation in a concentration-dependent fashion[1].Treatment of cells with YKL-5-124 as a competitor at a concentration of about 30 nM blocks pull-down of CDK7-cyclin H but has no effect on the pull-down of cyclin K-CDK12/13 in HAP1 cells. Treatment with 100 nM YKL-5-124 reduces CDK7-cyclin H binding to bioTHZ1 by >50% at 30 min[1].