title: Fission yeast Pot1 and RecQ helicase are required for efficient chromosome segregation.
abstract: Pot1 is a single-stranded telomere-binding protein that is conserved from fission yeast to mammals. Deletion of Schizosaccharomyces pombe pot1(+) causes immediate telomere loss. S. pombe Rqh1 is a homolog of the human RecQ helicase WRN, which plays essential roles in the maintenance of genomic stability. Here, we demonstrate that a pot1Δ rqh1-hd (helicase-dead) double mutant maintains telomeres that are dependent on Rad51-mediated homologous recombination. Interestingly, the pot1Δ rqh1-hd double mutant displays a "cut" (cell untimely torn) phenotype and is sensitive to the antimicrotubule drug thiabendazole (TBZ). Moreover, the chromosome ends of the double mutant do not enter the pulsed-field electrophoresis gel. These results suggest that the entangled chromosome ends in the pot1Δ rqh1-hd double mutant inhibit chromosome segregation, signifying that Pot1 and Rqh1 are required for efficient chromosome segregation. We also found that POT1 knockdown, WRN-deficient human cells are sensitive to the antimicrotubule drug vinblastine, implying that some of the functions of S. pombe Pot1 and Rqh1 may be conserved in their respective human counterparts POT1 and WRN.
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Takahashi
authors.forename: Ryota
authors.initials: R
authors.lastname: Imano
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kibe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Seimiya
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Muramatsu
authors.forename: Naoki
authors.initials: N
authors.lastname: Kawabata
authors.forename: Genki
authors.initials: G
authors.lastname: Tanaka
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Taisuke
authors.initials: T
authors.lastname: Hiromoto
authors.forename: Yuka
authors.initials: Y
authors.lastname: Koizumi
authors.forename: Norihiko
authors.initials: N
authors.lastname: Nakazawa
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yanagida
authors.forename: Masashi
authors.initials: M
authors.lastname: Yukawa
authors.forename: Eiko
authors.initials: E
authors.lastname: Tsuchiya
authors.forename: Masaru
authors.initials: M
authors.lastname: Ueno
mesh_terms: D020090:Chromosome Segregation / Q000187:drug effects; D015825:Chromosomes, Fungal / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism*; D005090:Exodeoxyribonucleases / Q000378:metabolism; D020868:Gene Silencing / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D050296:Microbial Viability / Q000187:drug effects; D008938:Mitosis / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D053484:RecQ Helicases / Q000378:metabolism; D011995:Recombination, Genetic / Q000187:drug effects; D051716:Replication Protein A / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism*; D000089804:Shelterin Complex; D016615:Telomere / Q000378:metabolism; D034501:Telomere-Binding Proteins / Q000378:metabolism*; D013827:Thiabendazole / Q000494:pharmacology; D014747:Vinblastine / Q000494:pharmacology; D000071657:Werner Syndrome Helicase
chemical_list: C440849:POT1 protein, human; D051716:Replication Protein A; D029702:Schizosaccharomyces pombe Proteins; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins; C499082:pot1 protein, S pombe; D014747:Vinblastine; D005090:Exodeoxyribonucleases; D004265:DNA Helicases; D053484:RecQ Helicases; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase; C106462:Rqh1 protein, S pombe; D013827:Thiabendazole