Yeast Ku as a regulator of chromosomal DNA end structure.
During telomere replication in yeast, chromosome ends acquire an S-phase-specific overhang of the guanosine-rich strand. Here it is shown that in cells lacking Ku, a heterodimeric protein involved in nonhomologous DNA end joining, these overhangs are present throughout the cell cycle. In vivo cross-linking experiments demonstrated that Ku is bound to telomeric DNA. These results show that Ku plays a direct role in establishing a normal DNA end structure on yeast chromosomes, conceivably by functioning as a terminus-binding factor. Because Ku-mediated DNA end joining involving telomeres would result in chromosome instability, our data also suggest that Ku has a distinct function when bound to telomeres.
Gravel
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Département de Microbiologie et Infectiologie, Faculté de Médecine, Université de Sherbrooke, 3001 12th Avenue Nord, Sherbrooke, Quebec QC J1H 5N4, Canada.
Larrivée
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Labrecque
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Wellinger
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D034961:Antigens, Nuclear; D001665:Binding Sites; D015825:Chromosomes, Fungal / Q000737:chemistry / Q000378:metabolism*; D004265:DNA Helicases; D004271:DNA, Fungal / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D016195:G2 Phase; D005800:Genes, Fungal; D000072200:Ku Autoantigen; D008938:Mitosis; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D016196:S Phase; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D019098:Telomerase / Q000235:genetics / Q000378:metabolism; D016615:Telomere / Q000378:metabolism*; D013696:Temperature; D014170:Transformation, Genetic
D034961:Antigens, Nuclear; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; C081647:high affinity DNA-binding factor, S cerevisiae; D019098:Telomerase; D004265:DNA Helicases; C106893:XRCC5 protein, human; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen