Coordinated Action of Nap1 and RSC in Disassembly of Tandem Nucleosomes.
The SWI/SNF and RSC family of ATP-dependent chromatin remodelers disassembles nucleosomes by moving nucleosomes into the vicinity of adjoining nucleosomes. We found that the histone chaperone Nap1 efficiently promotes disassembly of adjacent nucleosomes with which RSC collides and not the disassembly of nucleosomes mobilized by RSC. Nap1 is specific to RSC, as it does not target SWI/SNF, its paralog in Saccharomyces cerevisiae Extensive mutational analysis of Nap1 has revealed that Nap1 affinity for histones H2A-H2B and H3-H4 and its ability to displace histones from DNA are required for Nap1 to enhance RSC-mediated disassembly. Other histone chaperones, such as Vps75, that also bind histones are not able to enhance RSC-mediated disassembly. Our study suggests a mechanism by which Nap1 is recruited to actively transcribed regions and assists in the passage of the transcription complex through chromatin, and it provides a novel mechanism for the coordinated action of RSC and Nap1.
University of Texas M. D. Anderson Cancer Center, Department of Epigenetics and Molecular Carcinogenesis, Smithville, Texas, USA Center for Cancer Epigenetics, University of Texas M. D. Anderson Cancer Center, Smithville, Texas, USA.
Rashmi
R
Prasad
University of Colorado at Boulder, Department of Chemistry and Biochemistry, Boulder, Colorado, USA The University of Texas at Dallas, Department of Chemistry and Biochemistry, Dallas, Texas, USA.
Sheena
S
D'Arcy
University of Texas M. D. Anderson Cancer Center, Department of Epigenetics and Molecular Carcinogenesis, Smithville, Texas, USA.
Arjan
A
Hada
University of Colorado at Boulder, Department of Chemistry and Biochemistry, Boulder, Colorado, USA Howard Hughes Medical Institute, University of Colorado at Boulder, Boulder, Colorado, USA.
Karolin
K
Luger
University of Texas M. D. Anderson Cancer Center, Department of Epigenetics and Molecular Carcinogenesis, Smithville, Texas, USA Center for Cancer Epigenetics, University of Texas M. D. Anderson Cancer Center, Smithville, Texas, USA bbartholomew@mdanderson.org.
Blaine
B
Bartholomew
D002843:Chromatin / Q000378:metabolism; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D008958:Models, Molecular; D056490:Nucleosome Assembly Protein 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism*; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic
D002843:Chromatin; D004268:DNA-Binding Proteins; D006657:Histones; C533556:NAP1 protein, S cerevisiae; D056490:Nucleosome Assembly Protein 1; D009707:Nucleosomes; C103337:RSC complex, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors