Dr. Richard N. Day

        Dr. Richard Day joined the faculty at the University of Virginia in 1990. He is an associate professor in the departments of Medicine and Cell Biology. Dr. Day’s research interests are focused on understanding the network of regulatory protein interactions that function to control cell-type specific gene expression. The broad objective is to determine how transcription factors function to coordinate the activities of multiprotein complexes at specific gene enhancers and promoters. His laboratory uses biochemical and molecular approaches to define the network of protein interactions that are coordinated by specific transcription factors. These in vitro approaches are then complemented by non-invasive live-cell imaging techniques. Fluorescence microscopy is used to visualize the intranuclear distribution and behaviors of proteins that are labeled with different color variants of the marine invertebrate fluorescent proteins. His recent studies using these combined experimental approaches have begun to define how specific gene regulatory complexes are assembled in the intact cell nucleus, and have shown how certain disease-causing point mutations can affect these protein interactions. Dr. Day is an internationally recognized expert in live-cell imaging, and has published many papers and book chapters on this topic. He has taught in Cold Spring Harbor Laboratory live-cell imaging courses since 1998, and is the co-organizer of the annual Workshop on FRET microscopy at the University of Virginia.

Fluorescent Proteins from Marine Invertebrates - New Tools for Studying Protein Dynamics in Living Cells

          Over the past decade, we have witnessed remarkable advances in the application of light microscopy to visualize dynamic processes inside the living cell. The development of new fluorescent probes, coupled with advances in digital image acquisition and analysis, has dramatically improved our ability to obtain dynamic measurements of protein behavior. For example, biologists now have the enormous benefit of using gene-transfer approaches to label proteins inside the living cell with the jellyfish green fluorescent protein (GFP). The recent engineering of GFP, as well as the discovery of new fluorescent proteins (FPs) from marine invertebrates are yielding an assortment of fluorescent proteins that emit from the blue to the red range of the visible spectrum. The characteristics of these important new tools for live-cell imaging will be discussed. The FPs are now widely used as noninvasive markers in living cells because their fluorescence does not require the addition of cofactors. The FP-labeled proteins produced in cells are often indistinguishable from their endogenous counterparts, making them most useful for monitoring the subcellular localization and trafficking properties of proteins. Approaches to measure dynamic protein behavior in living cells will be considered, along with some of the new generation of FPs with useful optical marking characteristics that allow them to be switched between non-fluorescent and fluorescent states. The application of the FPs has transformed studies in cell biology by allowing the behavior of proteins to be tracked by fluorescence microscopy in their natural environment. The development of these novel probes and associated imaging approaches will continue to provide unique insights into the biology of living systems.