A02: Maintaining gene expression fidelity in response to DNA and RNA protein crosslinks

Fidelity of gene expression relies on an intact DNA template, yet human cells are exposed to different genotoxic stressors including ultraviolet light (UV), byproducts of metabolism such as formaldehyde (FA) or chemotherapy. Such stressors can induce helix-distorting pyrimidine dimers or covalent protein crosslinking to DNA and RNA, thus producing damage obstructing transcription, splicing and translation. A plethora of DNA repair as well as RNA and protein quality control pathways monitor gene expression at different levels and detect DNA lesions and aberrant RNAs, proteins, and protein complexes. Although the overarching mechanisms dealing with DNA- and RNA-protein crosslinks were described recently, the molecular determinants regulating transcription and downstream pre-mRNA processing in response to such transcription- and translation-blocking lesions remain poorly understood. With this project, we want to understand the molecular components that ensure fidelity of gene expression in the presence of DNA- and RNA-protein crosslinks interfering with transcription and splicing as cells age. We will combine quantitative proteomics with cutting edge genomics and genome editing to mechanistically dissect RNAPII-mediated transcription and splicing regulation in response to DNA- and RNA-protein crosslinks in the nucleus. We anticipate our work to provide new understanding of how such crosslinks affect faithful gene expression throughout the lifespan of cells.