title: Chromatin as dynamic 10-nm fibers.
abstract: Since Flemming described a nuclear substance in the nineteenth century and named it "chromatin," this substance has fascinated biologists. What is the structure of chromatin? DNA is wrapped around core histones, forming a nucleosome fiber (10-nm fiber). This fiber has long been assumed to fold into a 30-nm chromatin fiber and subsequently into helically folded larger fibers or radial loops. However, several recent studies, including our cryo-EM and X-ray scattering analyses, demonstrated that chromatin is composed of irregularly folded 10-nm fibers, without 30-nm chromatin fibers, in interphase chromatin and mitotic chromosomes. This irregular folding implies a chromatin state that is physically less constrained, which could be more dynamic compared with classical regular helical folding structures. Consistent with this, recently, we uncovered by single nucleosome imaging large nucleosome fluctuations in living mammalian cells (∼50 nm/30 ms). Subsequent computational modeling suggested that nucleosome fluctuation increases chromatin accessibility, which is advantageous for many "target searching" biological processes such as transcriptional regulation. Therefore, this review provides a novel view on chromatin structure in which chromatin consists of dynamic and disordered 10-nm fibers.
authors.affiliation: Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan, kmaeshim@nig.ac.jp.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Maeshima
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Imai
authors.forename: Sachiko
authors.initials: S
authors.lastname: Tamura
authors.forename: Tadasu
authors.initials: T
authors.lastname: Nozaki
mesh_terms: D000818:Animals; D002843:Chromatin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D006801:Humans; D008938:Mitosis; D009707:Nucleosomes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D002843:Chromatin; D009707:Nucleosomes
references.citation: J Cell Biol. 1994 Oct;127(2):287-302
references.pmid: 7929576
references.citation: Genome Res. 2013 Nov;23(11):1829-38
references.pmid: 24077391
references.citation: Cell. 1985 Nov;43(1):207-13
references.pmid: 4075395
references.citation: Cell. 2007 Feb 23;128(4):651-4
references.pmid: 17320503
references.citation: Annu Rev Biophys Biomol Struct. 2002;31:361-92
references.pmid: 11988475
references.citation: Biochim Biophys Acta. 2008 Dec;1783(12):2398-414
references.pmid: 18706456
references.citation: Chromosome Res. 2006;14(7):707-33
references.pmid: 17115328
references.citation: Curr Biol. 2002 Mar 19;12(6):439-45
references.pmid: 11909528
references.citation: EMBO Rep. 2012 Nov 6;13(11):992-6
references.pmid: 22986547
references.citation: Science. 2002 Sep 13;297(5588):1824-7
references.pmid: 12228709
references.citation: Science. 2009 Oct 9;326(5950):289-93
references.pmid: 19815776
references.citation: Adv Enzyme Regul. 2005;45:17-26
references.pmid: 16139341
references.citation: Curr Opin Genet Dev. 2009 Apr;19(2):159-65
references.pmid: 19346124
references.citation: Nat Methods. 2008 Feb;5(2):159-61
references.pmid: 18176568
references.citation: Annu Rev Biochem. 2005;74:595-648
references.pmid: 15952899
references.citation: J Struct Biol. 1999 Dec 1;128(1):106-18
references.pmid: 10600565
references.citation: Proc Natl Acad Sci U S A. 2009 Aug 11;106(32):13317-22
references.pmid: 19651606
references.citation: Chromosome Res. 2011 Jan;19(1):63-81
references.pmid: 21116704
references.citation: Crit Rev Eukaryot Gene Expr. 2000;10(2):179-212
references.pmid: 11186332
references.citation: EMBO Rep. 2012 Nov 6;13(11):943-4
references.pmid: 23041656
references.citation: J Biol Chem. 2008 Dec 12;283(50):34532-40
references.pmid: 18930918
references.citation: J Biochem. 2008 Feb;143(2):145-53
references.pmid: 17981824
references.citation: Trends Cell Biol. 2009 Nov;19(11):555-65
references.pmid: 19836954
references.citation: Exp Cell Res. 2012 Jul 15;318(12):1448-55
references.pmid: 22394510
references.citation: EMBO J. 1986 Mar;5(3):519-28
references.pmid: 3011410
references.citation: Proc Natl Acad Sci U S A. 2011 Oct 11;108(41):16992-7
references.pmid: 21969536
references.citation: Curr Opin Cell Biol. 2011 Feb;23(1):114-21
references.pmid: 20974528
references.citation: Methods Cell Biol. 1999;58:203-22
references.pmid: 9891383
references.citation: Biopolymers. 2013 Apr;99(4):225-32
references.pmid: 23348669
references.citation: Science. 1974 Jan 25;183(4122):330-2
references.pmid: 4128918
references.citation: J Cell Biol. 1983 Apr;96(4):1120-31
references.pmid: 6682117
references.citation: Q Rev Biophys. 1988 May;21(2):129-228
references.pmid: 3043536
references.citation: Exp Cell Res. 1976 Jan;97:101-10
references.pmid: 812708
references.citation: J Cell Biol. 1994 Apr;125(1):11-9
references.pmid: 8138565
references.citation: EMBO J. 1986 Jun;5(6):1395-402
references.pmid: 3755397
references.citation: Proc Natl Acad Sci U S A. 1976 Jun;73(6):1897-901
references.pmid: 1064861
references.citation: Nucleus. 2013 Sep-Oct;4(5):349-56
references.pmid: 23945462
references.citation: Semin Cell Dev Biol. 2007 Oct;18(5):651-8
references.pmid: 17905614
references.citation: Chromosoma. 1989 Aug;98(2):129-43
references.pmid: 2476279
references.citation: J Biol Chem. 2005 Sep 30;280(39):33552-7
references.pmid: 16079127
references.citation: Dev Cell. 2003 Apr;4(4):467-80
references.pmid: 12689587
references.citation: Nat Rev Mol Cell Biol. 2003 Oct;4(10):809-14
references.pmid: 14570061
references.citation: EMBO J. 2012 Apr 4;31(7):1644-53
references.pmid: 22343941
references.citation: Nat Struct Mol Biol. 2009 May;16(5):534-40
references.pmid: 19377481
references.citation: Curr Opin Cell Biol. 2006 Dec;18(6):632-8
references.pmid: 17046228
references.citation: Trends Biochem Sci. 2011 Jan;36(1):1-6
references.pmid: 20926298
references.citation: Nature. 1980 Dec 11;288(5791):620-2
references.pmid: 7442809
references.citation: Proc Natl Acad Sci U S A. 2004 Nov 23;101(47):16495-500
references.pmid: 15545610
references.citation: Micron. 2001 Jan;32(1):91-9
references.pmid: 10900384
references.citation: Nature. 2008 Jun 12;453(7197):948-51
references.pmid: 18463634
references.citation: Curr Opin Cell Biol. 2012 Jun;24(3):359-66
references.pmid: 22459407
references.citation: J Mol Biol. 2011 Dec 16;414(5):749-64
references.pmid: 22051513
references.citation: J Chem Phys. 2009 Aug 14;131(6):064905
references.pmid: 19691409
references.citation: J Cell Biol. 2013 Feb 18;200(4):429-41
references.pmid: 23401001
references.citation: Curr Biol. 2002 Mar 19;12(6):508-13
references.pmid: 11909539
references.citation: J Biol Chem. 2010 Oct 15;285(42):31954-64
references.pmid: 20720004
references.citation: Proc Natl Acad Sci U S A. 2008 Jul 1;105(26):8872-7
references.pmid: 18583476
references.citation: Chromosoma. 2013 Oct;122(5):377-86
references.pmid: 23818178
references.citation: Nat Rev Genet. 2001 Apr;2(4):292-301
references.pmid: 11283701
references.citation: Nature. 2012 Apr 11;485(7398):381-5
references.pmid: 22495304
references.citation: Genes Dev. 2012 Aug 1;26(15):1659-78
references.pmid: 22855829
references.citation: Mol Cell Biol. 2009 Jan;29(2):538-46
references.pmid: 19001093
references.citation: Cell. 1979 Aug;17(4):849-58
references.pmid: 487432
references.citation: Chromosome Res. 2001;9(1):77-80
references.pmid: 11272795
references.citation: Biophys J. 2005 Dec;89(6):4275-85
references.pmid: 16150965
references.citation: Cold Spring Harb Symp Quant Biol. 2010;75:439-44
references.pmid: 21447821
references.citation: Genome Res. 2010 Jun;20(6):761-70
references.pmid: 20430782
references.citation: Nucleic Acids Res. 2012 Aug;40(15):e119
references.pmid: 22844090
references.citation: Nature. 2012 Aug 2;488(7409):116-20
references.pmid: 22763441
references.citation: Curr Opin Cell Biol. 2010 Jun;22(3):291-7
references.pmid: 20346642
references.citation: Nucleus. 2012 Sep-Oct;3(5):404-10
references.pmid: 22825571
references.citation: J Cell Biol. 1984 Jul;99(1 Pt 1):42-52
references.pmid: 6736132
references.citation: PLoS One. 2010 Jun 09;5(6):e11039
references.pmid: 20543957
references.citation: Nat Rev Mol Cell Biol. 2006 May;7(5):311-22
references.pmid: 16633335
references.citation: Epigenetics Chromatin. 2012 Dec 21;5(1):20
references.pmid: 23259580
references.citation: Methods Mol Biol. 2009;464:415-23
references.pmid: 18951198
references.citation: Eur Biophys J. 1986;13(3):157-73
references.pmid: 3956445
references.citation: J Struct Biol. 2012 May;178(2):207-14
references.pmid: 22138167
references.citation: Cell Rep. 2012 Dec 27;2(6):1645-56
references.pmid: 23246002
references.citation: J Cell Biol. 1983 Apr;96(4):1132-7
references.pmid: 6833394
references.citation: Science. 2004 Nov 26;306(5701):1571-3
references.pmid: 15567867
references.citation: Curr Biol. 1996 Dec 1;6(12):1599-608
references.pmid: 8994824
references.citation: Cell. 2004 Sep 3;118(5):555-66
references.pmid: 15339661
references.citation: PLoS One. 2013 Oct 09;8(10):e75622
references.pmid: 24130727
references.citation: J Mol Biol. 2002 Jun 21;319(5):1097-113
references.pmid: 12079350
references.citation: Histochem Cell Biol. 2006 Jan;125(1-2):43-51
references.pmid: 16328430
references.citation: Semin Cell Dev Biol. 2007 Oct;18(5):676-81
references.pmid: 17920313
references.citation: Chromosome Res. 2006;14(1):17-25
references.pmid: 16506093
references.citation: Proc Natl Acad Sci U S A. 2008 Dec 16;105(50):19732-7
references.pmid: 19064912
references.citation: Nature. 2012 Apr 11;485(7398):376-80
references.pmid: 22495300
references.citation: Proc Natl Acad Sci U S A. 2006 Apr 25;103(17):6506-11
references.pmid: 16617109
references.citation: Exp Cell Res. 1986 Aug;165(2):291-7
references.pmid: 3720850
references.citation: J Mol Biol. 2003 Mar 14;327(1):85-96
references.pmid: 12614610
references.citation: Cell. 1982 May;29(1):171-81
references.pmid: 7105181
references.citation: Nature. 2005 Jul 7;436(7047):138-41
references.pmid: 16001076
references.citation: Exp Cell Res. 1999 Feb 25;247(1):176-88
references.pmid: 10047460
references.citation: Cold Spring Harb Symp Quant Biol. 1978;42 Pt 1:351-60
references.pmid: 277351
references.citation: J Cell Biol. 1998 Mar 23;140(6):1285-95
references.pmid: 9508763
references.citation: Curr Opin Struct Biol. 1996 Jun;6(3):334-41
references.pmid: 8804837
references.citation: Chromosome Res. 2011 Jul;19(5):579-90
references.pmid: 21656257
references.citation: Nature. 1953 Apr 25;171(4356):737-8
references.pmid: 13054692
references.citation: Science. 2013 Nov 22;342(6161):940-1
references.pmid: 24264982
references.citation: Science. 2001 Dec 7;294(5549):2181-6
references.pmid: 11739961
references.citation: EMBO J. 2012 Apr 4;31(7):1621-3
references.pmid: 22415369
references.citation: Cell. 1977 Nov;12(3):817-28
references.pmid: 922894
references.citation: Chromosoma. 2005 Nov;114(5):365-75
references.pmid: 16175370
references.citation: Phys Rev Lett. 2009 Jan 9;102(1):018101
references.pmid: 19257243
references.citation: Curr Opin Struct Biol. 2006 Jun;16(3):336-43
references.pmid: 16714106
references.citation: Cold Spring Harb Symp Quant Biol. 1978;42 Pt 1:331-50
references.pmid: 98280
references.citation: Science. 1974 May 24;184(4139):868-71
references.pmid: 4825889
references.citation: Bioessays. 2013 Sep;35(9):818-28
references.pmid: 23832846
references.citation: Curr Biol. 2001 Aug 21;11(16):1227-39
references.pmid: 11525737
references.citation: Biophys J. 2009 Feb 18;96(4):1617-28
references.pmid: 19217877
references.citation: Science. 2013 Nov 22;342(6161):948-53
references.pmid: 24200812
references.citation: J Cell Biol. 1998 Dec 14;143(6):1415-25
references.pmid: 9852140
references.citation: EMBO J. 2011 May 4;30(9):1778-89
references.pmid: 21468033
references.citation: Curr Biol. 2012 Dec 4;22(23):R1012-21
references.pmid: 23218009
references.citation: Cell. 2012 Feb 3;148(3):458-72
references.pmid: 22265598