Novel genes
involved in telomere length regulation in Saccharomyces cerevisiae.
Tal Yehuda,
Anat Krauskopf
Molecular Microbiology, Tel-Aviv University, Ramat Aviv, Tel-Aviv, 69978,
Israel (talye@tau.post.ac.il)
Telomeres are the physical ends of eukaryotic chromosomes. They provide a 'capping' function that protects chromosome ends from fusion, recombination and degradation. Within individuals of the same organism, the length of the telomere is tightly regulated. The mechanisms of length regulation are dependent on the binding of specific telomere binding proteins. Although these mechanisms are well established, more needs to be studied on how these complexes operate together. We have initiated a genome wide search for the identification of new proteins involved in telomere metabolism in the yeast Saccharomyces cerevisiae. Telomeric Southern blotting technique was used to screen deletion strains supplied by the S. cerevisiae Genome Deletion Project. We have currently screened 2,556 viable mutants. More than 70 genes involved in telomere length regulation were identified. Six genes were taken for further research. Three genes are related to the Pho family genes. The CDK-cyclin couple Pho80-Pho85 involved in phosphate regulation and pho87 involved in phosphate sensing. The Srb5p, which is a part of the SRB sub-complex of the mediator, involved in general transcription. The Mms19p which is known to be involved in transcription and Nucleotide Excision Repair. The Htl1p thought to be involved in chromosome segregation. These genes were classified to epistasis groups in relation to known genes that participate in telomere length regulation.