ldc000067 (ldc067) is a novel specific inhibitor of cdk9 with ic50 value of 44 ± 10 nm [1].cyclin-dependent kinase 9 (cdk9) is a cyclin-dependent kinase. cdk9 and cyclin t form the positive transcription elongation factor b (p-tefb) complex for rna polymerase ii and functions by phosphorylating the c-terminal domain of the largest subunit of rna polymerase ii [1].ldc000067 (ldc067) is a novel and highly specific cdk9 inhibitor. ldc000067 exhibited selectivity for cdk9 over other cdks in the range of 55-fold (vs. cdk2) to over 230-fold (vs. cdk6 and cdk7). ldc067 also inhibited transcription in a dose-dependent and atp-competitive manner. in whole cells, ldc000067 induced the tumor suppressor protein p53 activation and apoptosis. ldc000067 also selectively reduced short-lived mrnas, including those that encode regulators of apoptosis and proliferation such as myc and mcl1 [1].
[1]. albert tk, rigault c, eickhoff j, et al. characterization of molecular and cellular functions of the cyclin-dependent kinase cdk9 using a novel specific inhibitor. br j pharmacol, 2014, 171(1): 55-68.
