rna pol ii phosphorylation

Toyocamycin (Vengicide) 是放线菌类产生的腺苷类似物，为 X 盒结合蛋白 1 (XBP1) 抑制剂，抑制 IRE1α 诱导的 ATP 依赖性 XBP1 mRNA 的断裂，IC50值为 80 nM。它还诱导凋亡。

MFH290 is a novel cysteine (Cys)-directed covalent inhibitor of CDK12 13. MFH290 forms a covalent bond with Cys-1039 of CDK12, exhibits excellent kinome selectivity, inhibits the phosphorylation of serine-2 in the C-terminal domain (CTD) of RNA-polymerase II (Pol II), and reduces the expression of key DNA damage repair genes. Importantly, these effects were demonstrated to be CDK12-dependent as mutation of Cys-1039 rendered the kinase refractory to MFH290 and restored Pol II CTD phosphorylation and DNA damage repair gene expression. Consistent with its effect on DNA damage repair gene expression, MFH290 augments the antiproliferative effect of the PARP inhibitor olaparib.

CDK9-Cyclin T1 PPI-IN-1 (Compound B19) 是CDK9-Cyclin T1蛋白-蛋白相互作用的选择性抑制剂。该化合物能够有效抑制TNBC MDA-MB-231细胞系的细胞增殖(IC50: 0.044 μM)，诱导细胞凋亡，同时降低CDK9的转录活性并减少RNA Pol II CTD ser2的磷酸化，有效地抑制了4T1移植瘤模型小鼠中肿瘤的生长。