All of the information required to generate a complete organism is stored in the DNA in discrete units called genes. To decode this information, a large enzyme complex known as RNA polymerase II is required. RNA polymerase II transcribes individual genes into mRNA molecules, which encode proteins (enzymes) that carry out chemical reactions in the cell or serve as structural frameworks to give cells and tissues their architecture. Not all genes in a given cell are transcribed at once, and determining how and when RNA polymerase II transcribes a given gene (there are ~30,000 in humans and 6,000 in yeast) is an area of intense study. Understanding this process, known as gene regulation, is the key to understanding how cells become different from one another during embryonic development, how cells respond to their environment, and how organisms evolve. Errors in gene regulation by RNA polymerase II contribute to disease and changes in fitness (survival) of an organism.
This project is aimed at understanding one level of control of the RNA polymerase II complex. RNA polymerase is composed of many protein subunits, the largest of which is called Rpb1. Rpb1 carries out the enzymatic action in which RNA is synthesized during transcription of a gene. Many smaller subunits interact with Rpb1 at different stages of transcription to help direct Rpb1 to the correct DNA site at the start of the gene (initiation), to help Rpb1 travel along the length of the gene (elongation), and to signal Rpb1 to stop transcription at the end of the gene (termination). Determining when these subunits bind to Rpb1 is an important process that appears to be aided by an enzyme called Ess1. Ess1 is known as a peptidyl-prolyl cis/trans isomerase. Ess1 binds to Rpb1 and is hypothesized to induce conformational changes (called cis/trans isomerizations) in Rpb1. In this way, Ess1 might control subunit binding to Rpb1, and thus help coordinate the multiple steps of transcription (initiation, elongation, termination) needed to generate mRNA and small RNAs. This research project is designed to determine exactly how Ess1 affects Rpb1, and thus how it may play a key role in gene regulation by the RNA polymerase II complex.
Broader impact of project: The research project will provide an opportunity for fulltime, intensive scientific training for a postdoctoral fellow and a Ph.D. student. Training will be in the various disciplines of genetics, biochemistry, and molecular biology. The project will also engage college undergraduate students during the summer months as part of the Department's Research Experience for Undergraduates Program (also sponsored by the National Science Foundation). Summer students will participate in ongoing experimental research during which time they will learn the scientific method, including the making of hypotheses, designing experiments to test them, carrying out the appropriate control experiments, as well as thoughtful analysis and interpretation of data. As such, the project should help inspire as well as train the next generation of biological researchers. In addition, the results of the project will be disseminated to the public in the form of research publications, presentations at national meetings, and free distribution of valuable reagents and scientific resources (data, strains, antibodies, etc.) to other qualified investigators.
