Identification of myosin heavy chain in Saccharomyces cerevisiae.

Motility in biological systems is expressed in a variety of ways, such as cytoplasmic streaming, cell shaping, nuclear migration and muscle contraction. These functions are thought to be mediated by structural proteins, for example, myosin, actin and tubulin. The involvement of myosin in muscle contraction is well documented and this protein is implicated in generating the cleavage forces during cytokinesis in some non-muscle cells. Here, we report the isolation of a protein similar to myosin as judged by its biochemical and immunological properties, from the yeast Saccharomyces cerevisiae. Parts of the protein have been conserved through evolution at the protein and DNA sequence levels. The presence of this protein in the region bordering mother cell and bud, as revealed by immunofluorescence, suggests that it is involved in cell division.