RNA-Based Gene Expression and Regulation at Single-Molecule and Single-Cell Levels
报告介绍 Abstract： The efficiency, accuracy, and regulation of gene expression are offundamental importance to living systems. Single-molecule and single-cell imaging approaches have provided powerful means for studying these aspects of gene expression, allowing us to characterize the in vitro and in vivo dynamics of the gene expression machineryat unprecedented precision and depth. Here, I will present applications of such imaging approaches to study two classes of RNA molecules that perform diverse catalytic and regulatory functions during gene expression. First, I will discuss the use of single-molecule fluorescence resonance energy transfer to characterize the conformational dynamics of the ribosome as it translates anmRNA into the encoded protein product and the role that these conformational dynamics play in driving and regulating protein synthesis. Second, I will discuss the use of a new imaging and analysis platform based on super-resolution fluorescence microscopy,whichenabled the first in vivo determination of basepairing-mediated target search kinetics. Specifically, this platform was used to investigatethe target search kinetics of a stress-induced bacterial small RNA (sRNA) that induces the degradation of target mRNAs. The data reveal that thesRNA binds to a primary target mRNA in a reversible and dynamic fashion, and that formation of the sRNA-mRNA complexes is rate-limiting, dictating the overall efficiency of regulationin vivo. Examination of a secondary target indicated that differences in the target search kinetics contribute to setting the regulation priority among different target mRNAs. This super-resolution imaging and analysis approach provides a conceptual framework that can be generalized to other sRNA systems and other target search processes. Biosketch： Dr. Jingyi Fei graduated from University of Science and Technology of China, with a Bachelor’s degree in Physical chemistry in 2005. She received her Ph.D. from Department of Chemistry at Columbia University in 2010. Her doctoral work was focused on studying conformational dynamics of ribosomeusing single-molecule fluorescence techniques. During her graduate study, she was awarded Kasindorf Fellowship Award and Hammett Award from Columbia University. She then joined the NSF funded Center for the Physics of Living Cells at University of Illinois Urbana-Champaign as a postdoctoral fellow, whereshe took on a new direction and focused on non-coding RNA-mediated gene regulation at cellular level using super resolution imaging technique. Dr. Fei joined the Department of Biochemistry and Molecular Biology at The University of Chicago as an assistant professor in 2016 to continue the studies on RNA-mediated gene expression and regulation with single-molecule imaging techniques.