Molecular genetic techniques will be applied to study the molecular basis of cell motility in non-muscle cells. As a model system the myxomycete Physarum will be used. In this system meiotic gene mapping permits identification of mutants by classical genetic analysis, allowing long term studies on a variety of gene products important in cell motility. In Physarum, extensive biochemical studies indicate that the proteins actin and myosin produce the force required for cytoplasmic streaming. Calcium is believed to regulate the activity of Physarum actomyosin, perhaps by binding to the essential myosin light chain, LC-2. To verify this hypothesis, the principal investigator will identify the cloned gene coding for LC-2 and determine its nucleotide sequence. From this information the amino acid sequence of the protein will be deduced, and its ability to bind calcium determined by comparison with the amino acid sequences of known calcium binding proteins. The results of this project should shed light on the method of regulation of motility in non-muscle cells. The work will also provide evidence for the role of myosin light chains in actomyosin-based cell motility.
