Deciphering the phosphorylation pattern of RNA polymerase II for eukaryotic transcription

摘要

ABSTRACT The C-terminal domain (CTD) of the largest RNA polymerase II subunit is a unique CTD sequence (Y1S2P3T4S5P6S7) repeated many times and is mostly conserved in eukaryotes. This domain coordinates the recruitment of transcriptional factors to Pol II through its post-translational modifications, the loss of which cripples the highly efficient transcription process and causes the cell to die. The accurate phosphorylation state of different residues in the CTD heptad repeats by kinase and phosphatases is crucial to precisely recruiting proteins to mediate the transcription process. Our lab utilizes our extensive experience in protein chemistry to understand the precise pattern of phosphorylation during transcription by investigating the activity and specificity of these kinases and phosphatases. We seek to understand how the post-translational modifications of CTD are altered during biological events and how such changes are reflected in the outcome of transcription. We use multi-disciplinary methods including structural biology, biochemistry, mass spectrometry methodology, and global transcriptome analysis to investigate the molecular mechanism of how different modification states of RNA polymerase II coordinate the eukaryotic transcription. Equipped with extensive knowledge about the phosphatase function and activity, we further explore how the chemical inhibition of SCP1, a human phosphatase belonging to HAD superfamily, thwarts some of the growth glioblastoma cells. We utilized our experience in structural-based inhibitor design to identify covalent and non- covalent inhibitors targeting this unique phosphatase.