Early Chemotactic Signaling Mediated by an Unconventional Myosin

Chemotaxis is a remarkable process -- a small amount of a chemical cue in the environment can direct a cell or organism movement towards the source, like the smell of freshly baked bread draws us into the kitchen. The goal of our work is to understand the basic mechanism of chemotaxis using a simple model system for our studies, the social amoeba Dictyostelium. The chemotaxis pathway is highly conserved from amoebae to humans so what we learn from the amoebae can teach us about chemotaxis is a wide variety of organisms. A new player in the chemotaxis pathway named MyoG has been identified in Dictyostelium. MyoG is a member of a family of proteins called myosins that work as molecular motors, generating movements within cells. Our objective is to determine the role of MyoG in transmitting signals from outside of the cell to the machinery inside that is responsible for directing cell movement. Determining how and where MyoG acts in the chemotaxis pathway and identifying what other proteins it works in concert with will provide new information about the chemotaxis pathway. We will also search for similar proteins in mammalian cells as a first step towards understanding the fundamental mechanism of chemotaxis and how it has been so highly conserved through millions of years of evolution.

Broader Impacts: The proposed project will be used to introduce students at all levels (from high school through graduate school) to basic research methods and practice. Young students will work one-on-one with the PI on several subprojects specifically tailored to each student's talents. Each student will be taught scientific methods, encouraged to think through and answer their own questions, formulate new questions, and summarize results as the project proceeds. The PI actively participates in the development of lectures and laboratory modules for International Training Courses in Cell Biology & Biochemistry in Latin America based on the chemotaxis project. The goal of these courses is to foster interactions and relationships between US and South American students and investigators. Finally, a central web resource for information about the myosin superfamily, the Myosin Home Page, will be adopted, updated and maintained. It will serve as a comprehensive resource for students and non-myosin researchers to gain basic information about the function of individual members of the large myosin superfamily of molecular motors.