Genetic regulation of telomere-telomere fusions in the yeast Saccharomyces cerevisae
AUTOR(ES)
Mieczkowski, Piotr A.
FONTE
National Academy of Sciences
RESUMO
Yeast strains with mutations in both TEL1 and MEC1 have short telomeres and elevated rates of chromosome deletions. By using a PCR assay, we demonstrate that mec1 tel1 strains also have telomere–telomere fusions (T-TFs). T-TFs require Lig4p (a ligase required for nonhomologous end-joining DNA repair). The highest rates of T-TFs are found in strains with combination of mutations that affect telomere length and DNA damage checkpoints (mec1 tel1, mec3 tel1, mre11 mec1, and ddc1 tel1 strains). Examining many mutant genotypes, we find good agreement between the level of T-TFs and the rate of chromosomal deletions. In addition, if telomeres are elongated in a mec1 tel1 strain, we eliminate T-TFs and reduce the deletion rate. The correlation between the level of T-TFs and the rate of deletions argues that many of these deletions reflect a cycle of T-TF formation (resulting in dicentric chromosomes), followed by chromosome breakage.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=196892Documentos Relacionados
- Telomere-Telomere Recombination Is an Efficient Bypass Pathway for Telomere Maintenance in Saccharomyces cerevisiae
- Origin of human chromosome 2: an ancestral telomere-telomere fusion.
- RAP1 stimulates single- to double-strand association of yeast telomeric DNA: implications for telomere-telomere interactions.
- Extrachromosomal Telomeric Circles Contribute to Rad52-, Rad50-, and Polymerase δ-Mediated Telomere-Telomere Recombination in Saccharomyces cerevisiae
- Involvement of Replicative Polymerases, Tel1p, Mec1p, Cdc13p, and the Ku Complex in Telomere-Telomere Recombination