yFACT induces global accessibility of nucleosomal DNA without H2A-H2B displacement.
FACT has been proposed to function by displacing H2A-H2B dimers from nucleosomes to form hexasomes. Results described here with yeast FACT (yFACT) suggest instead that nucleosomes are reorganized to a form with the original composition but a looser, more dynamic structure. First, yFACT enhances hydroxyl radical accessibility and endonuclease digestion in vitro at sites throughout the nucleosome, not just in regions contacted by H2A-H2B. Accessibility increases dramatically, but the DNA remains partially protected. Second, increased nuclease sensitivity can occur without displacement of dimers from the nucleosome. Third, yFACT is required for eviction of nucleosomes from the GAL1-10 promoter during transcriptional activation in vivo, but the preferential reduction in dimer occupancy expected for hexasome formation is not observed. We propose that yFACT promotes a reversible transition between two nucleosomal forms, and that this activity contributes to the establishment and maintenance of the chromatin barrier as well as to overcoming it.
Xin
Hua
H
Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, 84112, USA.
Takahata
Shinya
S
Blanksma
Mary
M
McCullough
Laura
L
Stillman
David J
DJ
Formosa
Tim
T
D042002:Chromatin Assembly and Disassembly / Q000502:physiology*; D004271:DNA, Fungal / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D019281:Dimerization; D006609:High Mobility Group Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006657:Histones / Q000378:metabolism*; D008957:Models, Genetic; D008958:Models, Molecular; D009707:Nucleosomes / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology; D035602:Transcriptional Elongation Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; C541535:FACT protein, S cerevisiae; D006609:High Mobility Group Proteins; D006657:Histones; D009707:Nucleosomes; C106768:POB3 protein, S cerevisiae; C071238:SPT16 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C024388:CTGCAG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific; C035594:TTTAAA -specific type II deoxyribonucleases
Mol Biosyst. 2008 Nov;4(11):1085-93
18931784
J Biol Chem. 2006 Aug 18;281(33):23297-301
16766522
Mol Cell Biol. 2001 May;21(10):3491-502
11313475
J Biol Chem. 2003 Nov 14;278(46):45288-95
12952948
Nature. 1999 Jul 15;400(6741):284-8
10421373
Biochemistry. 1999 Jul 13;38(28):8961-71
10413469
Mol Cell. 2009 May 14;34(4):405-15
19481521
Science. 2003 Aug 22;301(5636):1090-3
12934006
J Biol Chem. 2008 Feb 22;283(8):5058-68
18089575
Mol Cell Biol. 2004 May;24(9):3907-17
15082784
Methods Enzymol. 1999;304:3-19
10372352
EMBO J. 1999 May 4;18(9):2563-79
10228169
Cell. 1998 Jan 9;92(1):105-16
9489704
EMBO J. 2001 Sep 17;20(18):5207-18
11566884
Nat Struct Mol Biol. 2007 Nov;14(11):989-96
17984961
Genetics. 2007 Sep;177(1):101-12
17603125
Methods. 2001 Mar;23(3):233-9
11243836
Mol Cell Biol. 2003 Nov;23(22):8323-33
14585989
J Mol Biol. 2000 Mar 3;296(4):979-87
10686097
Genetics. 2002 Dec;162(4):1557-71
12524332
EMBO J. 2001 Jul 2;20(13):3506-17
11432837
Proc Natl Acad Sci U S A. 1983 Jan;80(1):51-5
6572008
Mol Cell. 2008 Apr 11;30(1):86-97
18406329
Science. 2003 Aug 22;301(5636):1096-9
12934008
Mol Cell Biol. 2005 Jul;25(14):5812-22
15987999
EMBO J. 2006 Oct 4;25(19):4479-89
16977311
Mol Cell. 2003 May;11(5):1311-22
12769854
Curr Opin Genet Dev. 2007 Apr;17(2):88-93
17307351
Methods Enzymol. 2004;377:322-43
14979035
Proc Natl Acad Sci U S A. 2008 Jul 1;105(26):8884-9
18579787
Methods Enzymol. 2004;375:211-28
14870669