Nearly all cells use an internal scaffolding system known as a cytoskeleton to control cell shape. The proteins that comprise this system have been known and well studied in large, complex eukaryotic cells for many decades, but were unknown in bacteria until only very recently. This project represents the first concerted attempt to characterize the bacterial actin-based cytoskeleton at the level of protein-protein interactions. It builds on a rich history of cytoskeletal research on eukaryotic cells and bridges the gap between the mature eukaryotic cytoskeleton field and the newly developing body of work addressing the basic cell biology of bacteria. It employs novel imaging techniques with established and new biochemical and biophysical approaches to address the means by which the proteins that comprise the bacterial cytoskeleton carry out their physiological roles and ultimately affect cellular behavior.
Broader Impact This project will broadly impact education and training; it will support outreach; and will benefit society scientifically. From the perspective of education and training, the majority of the proposed experiments will be carried out by graduate students. Indeed students will play an integral role in the intellectual development of all stages of the project, from developing and testing hypotheses to publication. Traditionally, all members of the PI's laboratory attend weekly laboratory meetings and journal clubs at which each member presents recent results and a paper from the literature. In support of outreach activities the PI will join a team of scientists at the University of Wisconsin-Madison who promote the development of interest in science for students in local K-12 schools. The PI's involvement in this Center for Biological Education will bring hands-on biological microscopy to local K-12 students to supplement the level of instruction available at the public schools. Students will be engaged in science modules based on optical microscopy as a part of after school programs, Saturday morning programs at local libraries, and/or Saturday morning programs at the University of Wisconsin-Madison. The scientific benefit to society of this project is reflected in the understanding that the existence of prokaryotic actins provides new perspectives on the evolution of the cytoskeleton, but just as importantly provides new reagents and the ability to test new hypotheses about the mechanisms of filament assembly and regulation. Identified structural, functional and sequence differences between prokaryotic and eukaryotic actins will provide insight into the limitations and range of functions of this important molecule. Additionally, knowledge gained toward these aims will significantly influence perspectives of the roles of actin in eukaryotic cell motility and cell division.
