Structural highlights
Function
CDK8_HUMAN Component of the Mediator complex, a coactivator involved in regulated gene transcription of nearly all RNA polymerase II-dependent genes. Mediator functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. Mediator is recruited to promoters by direct interactions with regulatory proteins and serves as a scaffold for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors. Phosphorylates the CTD (C-terminal domain) of the large subunit of RNA polymerase II (RNAp II), which may inhibit the formation of a transcription initiation complex. Phosphorylates CCNH leading to down-regulation of the TFIIH complex and transcriptional repression. Recruited through interaction with MAML1 to hyperphosphorylate the intracellular domain of NOTCH, leading to its degradation.[1] [2]
Publication Abstract from PubMed
CDK8 is a cyclin-dependent kinase that forms part of the mediator complex, and modulates the transcriptional output from distinct transcription factors involved in oncogenic control. Overexpression of CDK8 has been observed in various cancers, representing a potential target for developing novel CDK8 inhibitors in cancer therapeutics. In the course of our investigations to discover new CDK8 inhibitors, we designed and synthesized tricyclic pyrido[2,3-b][1,5]benzoxazepin-5(6H)-one derivatives, by introduction of chemical complexity in the multi-kinase inhibitor Sorafenib taking into account the flexibility of the P-loop motif of CDK8 protein observed after analysis of structural information of co-crystallized CDK8 inhibitors. In vitro evaluation of the inhibitory activity of the prepared compounds against CDK8 led us to identify compound 2 as the most potent inhibitor of the series (IC(50) = 8.25 nM). Co-crystal studies and the remarkable selectivity profile of compound 2 are presented. Compound 2 showed moderate reduction of phosphorylation of CDK8 substrate STAT1 in cells, in line with other reported Type II CDK8 inhibitors. We propose herein an alternative to find a potential therapeutic use for this chemical series.
Pyrido[2,3-b][1,5]benzoxazepin-5(6H)-one derivatives as CDK8 inhibitors.,Martinez-Gonzalez S, Garcia AB, Albarran MI, Cebria A, Amezquita-Alves A, Garcia-Campos FJ, Martinez-Gago J, Martinez-Torrecuadrada J, Munoz IG, Blanco-Aparicio C, Pastor J Eur J Med Chem. 2020 Sep 1;201:112443. doi: 10.1016/j.ejmech.2020.112443. Epub , 2020 Jun 20. PMID:32599324[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Akoulitchev S, Chuikov S, Reinberg D. TFIIH is negatively regulated by cdk8-containing mediator complexes. Nature. 2000 Sep 7;407(6800):102-6. PMID:10993082 doi:10.1038/35024111
- ↑ Fryer CJ, White JB, Jones KA. Mastermind recruits CycC:CDK8 to phosphorylate the Notch ICD and coordinate activation with turnover. Mol Cell. 2004 Nov 19;16(4):509-20. PMID:15546612 doi:S1097276504006409
- ↑ Martínez-González S, García AB, Albarrán MI, Cebriá A, Amezquita-Alves A, García-Campos FJ, Martínez-Gago J, Martínez-Torrecuadrada J, Muñoz IG, Blanco-Aparicio C, Pastor J. Pyrido[2,3-b][1,5]benzoxazepin-5(6H)-one derivatives as CDK8 inhibitors. Eur J Med Chem. 2020 Sep 1;201:112443. PMID:32599324 doi:10.1016/j.ejmech.2020.112443
