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Role of Exo1 nuclease in telomere DNA degradation in yku70/yku80 mutants of S. cerevisiae
Author(s) -
Ream Jennifer Anne,
Lewis L. Kevin
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.592.9
Subject(s) - telomere , genome instability , homologous recombination , saccharomyces cerevisiae , exonuclease , dna repair , non homologous end joining , biology , dna damage , telomere binding protein , mutant , replication protein a , microbiology and biotechnology , nuclease , mutation , dna , genetics , gene , dna binding protein , dna polymerase , transcription factor
DNA is constantly damaged within the cell by endogenous and environmental mutagens such as oxidative chemicals and radiation. Double‐strand breaks (DSBs) resulting from this damage are repaired by two pathways, homologous recombination (HR) and nonhomologous end‐joining (NHEJ). The molecular machinery involved in HR and NHEJ are conserved in vertebrates and yeast. The Ku protein complex is fundamental to initiation of the NHEJ pathway. The yeast Yku70/Yku80 protein complex is integral to the stabilization and replication of telomeres, in addition to its involvement in DSB repair. Budding yeast ( Saccharomyces cerevisiae ) yku70 mutants have been shown to be defective in NHEJ repair and have short telomeres. These mutants also display temperature sensitive growth at 37 °C, caused by telomere cap instability and telomere DNA degradation by Exo1 exonuclease at high temperature. Our genetic experiments demonstrate that pathways other than Exo1 telomere digestion are crucial for cell survival at 37 °C. Results of this work involving gene knockout experiments and cell survival assays will be presented.