Study of the influence of mutations in regulatory genes of the PHO system on mutation rates of the cells of yeast Saccharomyces cerevisiae.
Arseni Smirnov (1), Anastasia Fizikova (2), Elena Sambuk (2)
(1) 188309 Russia, Leningradskaya region, Gatchina, Slepneva st., 4-2-9; (2) Genetics and Selection, St.Petersburg state university, Universitetskaya, St. Petersburg, 199034, Russian Federation
Yeast S. cerevisiae are useful model object for estimating the frequency of spontaneous mutations affected by various factors of environment or resulted by metabolism damage and therefore by change of chemical composition of cell. Phosphate is the one of the necessary components of the media. Phosphate metabolism genes, coding the structure of phosphatase, polyphosphatase and other proteins, are regulated by activators Pho2p, Pho4p and also cyclin-CDK complex Pho80p-Pho85p. It was shown that disruption of PHO85 gene had a number of pleotropic effects, such as accumulation of ts, [rho - ] and pho4 mutations. In our work we used yeast strain 8C-YUNI101 with different kinds of mutations. Using this one we constructed strain with disruption of PHO85 gene coding cyclin-dependent phosphoproteinkinase. We showed that disruption of gene PHO85 led to rising of spontaneous mutations rate in locus CAN1. And pho4 mutants appearing with high frequency on the colonies pho85::LEU2 had antimutator effect. We suggest that Pho85p and Pho4p proteins are involved in signal pathways maintaining genetic material stability.