title: Condensin confers the longitudinal rigidity of chromosomes.
abstract: In addition to inter-chromatid cohesion, mitotic and meiotic chromatids must have three physical properties: compaction into 'threads' roughly co-linear with their DNA sequence, intra-chromatid cohesion determining their rigidity, and a mechanism to promote sister chromatid disentanglement. A fundamental issue in chromosome biology is whether a single molecular process accounts for all three features. There is universal agreement that a pair of Smc-kleisin complexes called condensin I and II facilitate sister chromatid disentanglement, but whether they also confer thread formation or longitudinal rigidity is either controversial or has never been directly addressed respectively. We show here that condensin II (beta-kleisin) has an essential role in all three processes during meiosis I in mouse oocytes and that its function overlaps with that of condensin I (gamma-kleisin), which is otherwise redundant. Pre-assembled meiotic bivalents unravel when condensin is inactivated by TEV cleavage, proving that it actually holds chromatin fibres together.
authors.affiliation: Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Houlard
authors.affiliation: Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Godwin
authors.affiliation: Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
authors.forename: Jean
authors.initials: J
authors.lastname: Metson
authors.affiliation: Laboratory of Developmental Biotechnology, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
authors.forename: Jibak
authors.initials: J
authors.lastname: Lee
authors.affiliation: Chromosome Dynamics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Hirano
authors.affiliation: Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
authors.forename: Kim
authors.initials: K
authors.lastname: Nasmyth
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics*; D002842:Chromatids; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics*; D020090:Chromosome Segregation / Q000502:physiology*; D002875:Chromosomes / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D008540:Meiosis / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics*; D009865:Oocytes / Q000166:cytology
chemical_list: D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; C572282:Ncaph2 protein, mouse; D009687:Nuclear Proteins; C108312:condensin complexes; D000251:Adenosine Triphosphatases