title: Csm4-dependent telomere movement on nuclear envelope promotes meiotic recombination.
abstract: During meiotic prophase, chromosomes display rapid movement, and their telomeres attach to the nuclear envelope and cluster to form a "chromosomal bouquet." Little is known about the roles of the chromosome movement and telomere clustering in this phase. In budding yeast, telomere clustering is promoted by a meiosis-specific, telomere-binding protein, Ndj1. Here, we show that a meiosis-specific protein, Csm4, which forms a complex with Ndj1, facilitates bouquet formation. In the absence of Csm4, Ndj1-bound telomeres tether to nuclear envelopes but do not cluster, suggesting that telomere clustering in the meiotic prophase consists of at least two distinct steps: Ndj1-dependent tethering to the nuclear envelope and Csm4-dependent clustering/movement. Similar to Ndj1, Csm4 is required for several distinct steps during meiotic recombination. Our results suggest that Csm4 promotes efficient second-end capture of a double-strand break following a homology search, as well as resolution of the double-Holliday junction during crossover formation. We propose that chromosome movement and associated telomere dynamics at the nuclear envelope promotes the completion of key biochemical steps during meiotic recombination.
authors.affiliation: Institute for Protein Research, Graduate School of Science, Osaka University, Suita, Osaka, Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Kosaka
authors.forename: Miki
authors.initials: M
authors.lastname: Shinohara
authors.forename: Akira
authors.initials: A
authors.lastname: Shinohara
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D023902:Chromosome Pairing; D008540:Meiosis; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009685:Nuclear Envelope / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D016615:Telomere / Q000235:genetics* / Q000378:metabolism
chemical_list: C530079:CSM4 protein, S cerevisiae; D018797:Cell Cycle Proteins; D008565:Membrane Proteins; C471174:Mps3 protein, S cerevisiae; C433703:Ndj1 protein, S cerevisiae; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins