Regulation of transcription coupled DNA repair

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Nucleotide excision repair (NER) is a conserved DNA repair process that removes bulky and/or helix-distorting lesions in damaged DNA. Transcription coupled repair (TCR) and global genomic repair (GGR) are two pathways that constitute NER. TCR is triggered by stalling of RNA polymerase II (RNAPII) at DNA damage sites and is dedicated to rapid removal of lesions in the transcribed strand of actively transcribed genes. TCR in eukaryotic cells is a complicated process and the underlying molecular mechanisms remain largely unresolved. In this project, a variety of approaches, including yeast genetics and proteomics, will be used to address long-standing questions about how TCR is regulated. This research on a fundamental DNA repair pathway will yield new insights into biological processes that maintain genome stability in the face of constant exposure to DNA damage. The project also includes substantive educational components, including training of graduate and undergraduate students as well as STEM outreach to local school students. The project has three objectives. The first will address how the RNAPII stalk, consisting of Rpb4 and Rpb7 proteins, regulates TCR. Rpb4 and Rpb7 can either repress or facilitate TCR and directly interact with many as-yet-unidentified proteins. Rpb4 and Rpb7-interacting proteins will be identified and their functions in TCR will be analyzed. The second objective will examine how TCR facilitators, including Rad26, Rpb9, Sen1 and Elf1, interplay with each other, with the TCR repressors Spt4/Spt5, and with RNAPII to regulate transcriptional lesion bypass and TCR. Finally, the third objective will investigate the role of the Pleckstrin homology domain (PHD) of Tfb1, a TFIIH subunit, in TCR and GGR. Together these studies will advance our understanding of the molecular mechanisms of transcription coupled DNA repair.This research is funded by the Genetic Mechanisms program in the Division of Molecular and Cellular Biosciences in the Directorate of Biological Sciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.