Intellectual merit. Proteins are complex biomolecules that regulate nearly every cellular process. A long-standing paradigm is that the structure of a protein, that is, the three-dimensional arrangement of its atoms, determines how the protein functions. Research over the past decade, however, has uncovered a vast universe of intrinsically disordered proteins (IDPs) that carry out their functions through flexible regions that do not have a well-defined three-dimensional structure. The growing recognition of the importance of IDPs is overturning long-held ideas about the connections between protein structure and protein function. In cells, protein molecules are packed tightly together leading to a phenomenon known as crowding. Crowding is known to affect structured proteins, but much less is known about the effects of crowding on IDPs. While it is clear that IDPs lack structure under pristine laboratory conditions, it is not at all clear whether such proteins remain unstructured in highly crowded environments found inside cells. Thus considerable effort has been directed at understanding the effects of crowding on IDPs. Such efforts include attempts to simulate crowding in the laboratory and efforts to probe IDPs directly in cells. Despite advances, obtaining information about IDP structure under crowded conditions remains challenging. Until this challenge is met, understanding of IDP function will be limited. Therefore, the goal of this project is to understand how crowding affects the structure and flexibility of IDPs. In this project, the effects of crowding on a panel of IDPs will be determined. The expected outcomes will be (1) new insight into the effects of crowding on IDPs and (2) transformative methodology that can be used to obtain information about the behavior of other IDPs under crowded conditions. Successful completion of this research will lead to a deeper understanding of how intrinsically disordered proteins function in the cell.
Broader impacts. This project will advance discovery while promoting teaching and learning by engaging both undergraduates and graduate students to answer fundamentally important questions about protein structure. The educational objective of this proposal is to enable broad dissemination of the principles of molecular structure and their impact on biology, by developing a course that increases scientific literacy, develops future science teachers, and shares knowledge with the local community. Through its educational objective, this project will have important societal benefits by broadly disseminating the principles of molecular structure to undergraduate students and the general public, by developing an understanding of how these principles apply to modern life, by supporting the development of future secondary science teachers, and by increasing understanding of scientific research. Finally, this research will broaden participation of underrepresented groups by supporting underrepresented groups in science.
