Biochemistry Department Seminar: Dr. Timothy J. Stasevich
Monday, October 5, 2020, 4:00pm
Timothy J. Stasevich, Ph.D. Associate Professor
CSU Monfort Professor
Dept. of Biochemistry and Molecular Biology Colorado State University
Fort Collins, CO, 80523 USA
Title: “Real-time quantification of gene expression with single-molecule precision in living cells”
This seminar will be given online via Zoom.
Meeting ID: 943 77216 239
My lab is creating technology to image gene expression in real time and with single-molecule precision in living cells. Using tandem-repeat mRNA and protein tags, genetically encoded intrabodies, and single-molecule microscopy, we now regularly image the live-cell translation dynamics of single mRNAs. In this talk, I will introduce our technology and describe how it can be used to amplify fluorescent signals within single translation sites. I will show how we quantify these signals to determine the size, shape, subcellular localization, and mobilities of translation sites, as well as their ribosomal densities and translational initiation and elongation kinetics. I will then highlight a few recent applications of our technology, including the imaging of translation shutdown during cellular stress, HIV-1 translational frameshifting, and non-canonical translation initiation at internal ribosomal entry sites. I will conclude by discussing new intrabodies my lab has engineered that bind the classic HA and FLAG epitopes in living cells. As these intrabodies can be encoded on plasmids, they can easily be adapted by other labs to image translation in multiple colors and in diverse living systems.
Timothy J. Stasevich is an Associate Professor in the Department of Biochemistry and Molecular Biology at Colorado State University (CSU). His lab uses a combination of advanced fluorescence microscopy, genetic engineering, and computational modeling to study the dynamics of gene regulation in living mammalian cells. His lab helped pioneer the imaging of real-time single- mRNA translation dynamics in living cells1. Dr. Stasevich received his B.S. in Physics and Mathematics from the University of Michigan, Dearborn, and his Ph. D. in Physics from the University of Maryland, College Park. He transitioned into experimental biophysics as a post- doctoral research fellow in the laboratory of Dr. James G.McNally at the National Cancer Institute. During this time, he developed technology based on fluorescence microscopy to help establish gold-standard measurements of live-cell protein dynamics. Dr. Stasevich next moved to Osaka University, where he worked with Dr. Hiroshi Kimura as a Japan Society for the Promotion of Science Foreign Postdoctoral Research Fellow. While there, he helped create technology to image endogenous proteins and their post-translation modifications in vivo. This allowed him to image the live-cell dynamics of epigenetic histone modifications during gene activation for the first time2. Before joining the faculty at CSU, Dr. Stasevich spent a year as a Visiting Fellow at the HHMI Janelia Research Campus, where he applied superresolution fluorescence microscopy to improve the spatiotemporal resolution of endogenous protein imaging in live cells.
1. Morisaki, T. et al. Real-time quantification of single RNA translation dynamics in living cells.
Science 352, 1425–1429 (2016).
2. Stasevich, T. J. et al. Regulation of RNA polymerase II activation by histone acetylation in single living cells. Nature 516, 272–275 (2014).