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Albrecht von Arnim

Date & Location: October 5, 2020, at 4p; Virtual visit

Subject: An old dog with new tricks: How protein synthesis responds to the chloroplast

Host: Polly Hsu

About the Speaker

University: University of Tennessee-Knoxville

Research Interests: Gene expression encompasses a complex panoply of molecular and biochemical processes whereby organisms convert the heritable information stored in the genome into molecules, cells and beyond. RNA is central to gene expression. The regulation of protein synthesis (translation) on the ribosome in particular remains incompletely understood, although translational control affords a rapid and reversible layer of control that amplifies changes in gene activity at the level of transcription. How do plants utilize translational control to adapt to changes in the environment? How does translational control contribute to plant development? These are some of the overarching questions that guide the research in our lab. We use the reference plant Arabidopsis thaliana because of the excellent genetic resources available in this species. In recent years, discoveries in our lab and elsewhere have opened the door to better understand the molecular signaling pathways that control translation in response to cues internal or external to the cell. We utilize a multi-pronged approach, combining genome-wide assays of translational efficiency with genetic analysis of Arabidopsis mutants, reporter gene expression assays and bioinformatic analysis. Leveraging the outstanding local expertise in computational biology, we are also pursuing mathematical models that illuminate these complex events. Our work has exemplified how generic translation initiation factors can contribute to the sequence-specific regulation of translational efficiency. It has highlighted that many eukaryotic mRNAs engage the ribosome itself to regulate translation through so-called upstream open reading frames. We also elaborated how the circadian clock cooperates with external signals to orchestrate the translatome over the course of the day-night cycle. Experiments such as these are revealing systematically which mRNAs are bundled together into regulons of translational control. This work helps us to understand how plants adapt to their environment and leads to novel ways to manipulate gene expression for biotechnological applications.