Areas of Interest

Research Interests

Transcription regulation, Mediator, Pol II, cryo-EM

In eukaryotes, the transcription of protein-coding genes and a majority of long non-coding RNAs relies on RNA polymerase II (Pol II). This process is intricately regulated through the collaborative efforts of various transcription factors. The integral component in this regulatory network is the mediator of RNA polymerase II transcription. Mediator is a large and modular complex that plays a crucial role in the transcriptional activation of RNA polymerase II.

The eukaryotic transcriptional Mediator is composed of a substantial Core component (cMED) and a detachable CDK8 kinase module (CKM). cMED serves as the platform for recruiting RNA polymerase II (Pol II) and facilitating the formation of the pre-initiation complex. Intriguingly, activity of Mediator in this context is regulated by its dissociable CDK8 kinase module through mechanisms that are not yet fully elucidated. To unravel the intricacies of this repression mechanism, we employed cryogenic-electron microscopy (cryo-EM) to achieve near-atomic resolution of the complex. Additionally, we utilized a diverse set of biochemical and biophysical tools, including RNA sequencing (RNA seq), chromatin immunoprecipitation sequencing (ChIP seq), in vitro transcription assays, and luciferase assays. These approaches collectively provided insights into how the CKM exerts its influence on Pol II recruitment within the context of cMED. Our integrated methodology aimed to shed light on the molecular details governing this crucial aspect of eukaryotic transcriptional regulation.