TY - JOUR

T1 - Novel functional requirements for non-homologous DNA end joining in Schizosaccharomyces pombe

AU - Manolis, K G

AU - Nimmo, E R

AU - Hartsuiker, E

AU - Carr, A M

AU - Jeggo, P A

AU - Allshire, R C

PY - 2001/1/15

Y1 - 2001/1/15

N2 - DNA double strand break (DSB) repair by non-homologous end joining (NHEJ) in mammalian cells requires the Ku70-Ku80 heterodimer, the DNA-PK catalytic subunit DNA-PKcs, as well as DNA ligase IV and Xrcc4. NHEJ of plasmid DSBs in Saccharomyces cerevisiae requires Ku, Xrcc4 and DNA ligase IV, as well as Mre11, Rad50, Xrs2 and DNA damage checkpoint proteins. Saccharomyces cerevisiae Ku is also required for telomere length maintenance and transcriptional silencing. We have characterized NHEJ in Schizosaccharomyces pombe using an extrachromosomal assay and find that, as anticipated, it is Ku70 and DNA ligase IV dependent. Unexpectedly, we find that Rad32, Rad50 (the S.pombe homologues of Mre11 and Rad50, respectively) and checkpoint proteins are not required for NHEJ. Furthermore, although S.pombe Ku70 is required for maintenance of telomere length, it is dispensable for transcriptional silencing at telomeres and is located throughout the nucleus rather than concentrated at the telomeres. Together, these results provide insight into the mechanism of NHEJ and contrast significantly with recent studies in S.cerevisiae.

AB - DNA double strand break (DSB) repair by non-homologous end joining (NHEJ) in mammalian cells requires the Ku70-Ku80 heterodimer, the DNA-PK catalytic subunit DNA-PKcs, as well as DNA ligase IV and Xrcc4. NHEJ of plasmid DSBs in Saccharomyces cerevisiae requires Ku, Xrcc4 and DNA ligase IV, as well as Mre11, Rad50, Xrs2 and DNA damage checkpoint proteins. Saccharomyces cerevisiae Ku is also required for telomere length maintenance and transcriptional silencing. We have characterized NHEJ in Schizosaccharomyces pombe using an extrachromosomal assay and find that, as anticipated, it is Ku70 and DNA ligase IV dependent. Unexpectedly, we find that Rad32, Rad50 (the S.pombe homologues of Mre11 and Rad50, respectively) and checkpoint proteins are not required for NHEJ. Furthermore, although S.pombe Ku70 is required for maintenance of telomere length, it is dispensable for transcriptional silencing at telomeres and is located throughout the nucleus rather than concentrated at the telomeres. Together, these results provide insight into the mechanism of NHEJ and contrast significantly with recent studies in S.cerevisiae.

KW - Animals

KW - Antigens, Nuclear

KW - Base Sequence

KW - Bleomycin

KW - Cell Nucleus

KW - DNA Damage

KW - DNA Helicases

KW - DNA Ligase ATP

KW - DNA Ligases

KW - DNA Repair

KW - DNA, Fungal

KW - DNA-Binding Proteins

KW - Fungal Proteins

KW - Gamma Rays

KW - Gene Silencing

KW - Ku Autoantigen

KW - Mammals

KW - Molecular Sequence Data

KW - Nuclear Proteins

KW - Restriction Mapping

KW - Saccharomyces cerevisiae Proteins

KW - Schizosaccharomyces

KW - Telomere

KW - Temperature

KW - Transcription Factors

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1093/emboj/20.1.210

DO - 10.1093/emboj/20.1.210

M3 - Article

C2 - 11226171

VL - 20

SP - 210

EP - 221

JO - EMBO Journal

JF - EMBO Journal

SN - 0261-4189

IS - 1-2

ER -