title: Calcium ions function as a booster of chromosome condensation.
abstract: Chromosome condensation is essential for the faithful transmission of genetic information to daughter cells during cell division. The depletion of chromosome scaffold proteins does not prevent chromosome condensation despite structural defects. This suggests that other factors contribute to condensation. Here we investigated the contribution of divalent cations, particularly Ca2+, to chromosome condensation in vitro and in vivo. Ca2+depletion caused defects in proper mitotic progression, particularly in chromosome condensation after the breakdown of the nuclear envelope. Fluorescence lifetime imaging microscopy-Förster resonance energy transfer and electron microscopy demonstrated that chromosome condensation is influenced by Ca2+. Chromosomes had compact globular structures when exposed to Ca2+and expanded fibrous structures without Ca2+. Therefore, we have clearly demonstrated a role for Ca2+in the compaction of chromatin fibres.
authors.affiliation: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan.
authors.forename: Rinyaporn
authors.initials: R
authors.lastname: Phengchat
authors.affiliation: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takata
authors.affiliation: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Morii
authors.affiliation: The Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-Cho Ikoma-shi, Nara 630-0192, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Inada
authors.affiliation: Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan.
authors.forename: Hideji
authors.initials: H
authors.lastname: Murakoshi
authors.affiliation: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Uchiyama
authors.affiliation: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan.
authors.forename: Kiichi
authors.initials: K
authors.lastname: Fukui
mesh_terms: D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D065096:Calcium Chelating Agents / Q000378:metabolism / Q000494:pharmacology; D002843:Chromatin / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D042002:Chromatin Assembly and Disassembly / Q000187:drug effects*; D042003:DNA Packaging / Q000187:drug effects*; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry; D016257:Fura-2 / Q000031:analogs & derivatives / Q000737:chemistry; D015870:Gene Expression; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008677:Metaphase / Q000187:drug effects*; D008856:Microscopy, Fluorescence; D009685:Nuclear Envelope / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D000097573:Red Fluorescent Protein
chemical_list: D002118:Calcium; D065096:Calcium Chelating Agents; D002843:Chromatin; D004533:Egtazic Acid; D005456:Fluorescent Dyes; D016257:Fura-2; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein; C485184:enhanced green fluorescent protein; C049925:fura-2-am; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid