YEAST DOM34 MUTANTS ARE DEFECTIVE IN MULTIPLE DEVELOPMENTAL PATHWAYS AND EXHIBIT DECREASED LEVELS OF POLYRIBOSOMES

The DOM34 gene of Saccharomyces cerevisiae is similar to genes found i n diverse eukaryotes and archaebacteria. Analysis of dom34 strains sho ws that progression through the G(1) phase of the cell cycle is delaye d, mutant cells enter meiosis aberrantly, and their ability to form ps eudohyphae is significantly diminished. RPS30A, which encodes ribosoma l protein S30, was identified in a screen for high-copy suppressors of the dom34 Delta growth defect. dom34 Delta mutants display an altered polyribosome profile that is rescued by expression of RPS30A. Taken t ogether, these data indicate that Dom34p functions in protein translat ion to promote G(1) progression and differentiation. A Drosophila homo log of Dom34p, pelota, is required for the proper coordination of meio sis and spermatogenesis. Heterologous expression of pelota in dom34 De lta mutants restores wild-type growth and differentiation, suggesting conservation of function between the eukaryotic members of the gene fa mily.