Structure-Function Mediated Regulation of TRPC1 Channel Activity

University Of North Dakota Main Campus, Grand Forks ND

Investigators

Abstract

Calcium ion (Ca2+) influx is an important fundamental player in how cytosolic molecules regulate cellular functions. Little is known about how the levels of cytosolic Ca2+ are regulated or about how Ca2+ enters the cell. Ca2+ influx in most cells occurs via the store/receptor-mediated Ca2+ entry mechanism, which is activated by depletion of Ca2+ from the internal Ca2+ stores. Recently, Drosophila homologues of a Ca2+ influx protein, the transient receptor potential (TRP) gene, have been identified in mammals and have been suggested to encode Ca2+ influx channels. Preliminary results suggests that one homolog, TRPC1, plays a critical role in Ca2+ influx across the plasma membrane and regulates several critical processes such as secretion, motility, growth, differentiation, and apoptosis. However, the mechanism of regulation of the activity of TRPC1 channel has not yet been established. The central hypothesis for this project is that TRPC1 function and regulation is mediated via its interaction with other proteins through specific domain(s) present on TRPC1. To test this hypothesis an interdisciplinary approach combining electrophysiological, molecular, and biochemical techniques, which will evaluate, characterize, and confirm the vital role of the TRPC1 multimerization domain will be used. Additionally, the role of a classical, calcium binding and regulatory protein, calmodulin, in activation/ inactivation of the TRPC1 channel, and in determining the role of another protein PICK1 in the regulation of TRPC1 will be investigated and validated. These studies will not only extend the basic understanding of how TRPC1 is regulated but will also provide important insights into the mechanisms underlying certain fundamental processes which are dependent on cytosolic Ca2+. This project integrates education with research efforts through development of relevant undergraduate- and graduate-level courses. These courses will address scientific literacy and will involve undergraduates and high school students (especially women and minorities) in research. The objectives are to help students develop critical thinking and problem solving skills, as well as enhance their potential as future scientists. Further, these educational experiences are being provided in a state that is demographically under-represented by biological research scientists.