Evolution and divergence of TBP-mediated transcription activation mechanisms

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A fundamental process in all living organisms is the flow of genetic information from DNA to RNA, known as transcription, which is mediated by the RNA polymerase enzyme. In eukaryotic organisms where the nucleus is enclosed by a membrane, there are three polymerases (Pol I, II, III) that transcribe different genes. The TATA-binding protein (TBP) which is a transcription factor (TF) found across all eukaryotic species, is required for the initiation of transcription by each of the three RNA Pols. Despite its conserved properties, TBP contains an N-terminal domain that has diversified in length and composition throughout evolution, hinting at a potential role in diversifying transcription mechanisms across eukaryotic species. The long-term goal of my Discovery research program is to understand how the highly conserved transcription process has evolved and diversified across Eukarya. Towards this goal, my five-year objectives are to: 1) examine the evolutionary role of the N-terminal domain of TBP in yeast and mammalian cells; 2) establish the molecular role of TBP N-terminal domain as it relates to transcription by the three RNA Pols; and 3) Determine the functional roles of vertebrate-specific TBP-related factors. My previous work on transcription factors highlights my expertise in the diverse technologies that I propose to use in my Discovery research program. For over two decades, scientists observed that TFs, key regulators of transcription, become excluded from chromosomes during mitosis, raising the question of how transcription is reactivated after mitosis. However, using gene editing, genomics, and live-cell imaging, I discovered that the observed TF exclusion was an artifact of chemical crosslinking, which was central to previously used techniques. My discovery led to a paradigm shift in our understanding of how transcription is restarted after mitosis, highlighting the powerful combination of gene editing, genomics, and single-molecule live-cell imaging to make unprecedented discoveries in basic biology. For my Discovery research program, I will use this previous experience and expertise to study the evolutionary influences that have shaped eukaryotic transcription. This research will help train Masters and PhD graduate students in emerging and interdisciplinary technologies, and support a lab environment where undergraduates can learn and perform independent study projects. I am committed to promoting an equitable training environment for underrepresented groups as described in the University of British Columbia's Equity and Diversity Strategic Plan. Because transcription is central to all life, the results of the proposed studies will have a major impact on advancing knowledge in diverse areas of natural sciences and genetic engineering. Knowledge gained from this basic biological research will have broader implications in the field of evolution and molecular biology, and will inform future basic research.