TY - JOUR
T1 - Expansion of chromosome territories with chromatin decompaction in BAF53-depleted interphase cells
AU - Lee, Kiwon
AU - Mi, Jin Kang
AU - Su, Jin Kwon
AU - Yunhee, Kim Kwon
AU - Ki, Woo Kim
AU - Lim, Jae Hwan
AU - Kwon, Hyockman
PY - 2007/10
Y1 - 2007/10
N2 - Chromosomes are compartmentalized into discrete chromosome territories during interphase in mammalian cells. A chromosome territory is generated by the tendency of chromatin to occupy the smallest shell volume, which is determined by the polymeric properties and interactions of the internal meshwork of the chromatin fiber. Here, we show that BAF53 knockdown by small interfering RNA interference led to the expansion of chromosome territories. This was accompanied by a reduction in chromatin compaction, an increase in the micrococcal nuclease sensitivity of the chromatin, and an alteration in H3-K9 and H3-K79 dimethylation. Interestingly, the BAF53 knockdown cells suffer a cell cycle defect. Despite the significant irregularity and decompaction of the polynucleosomes isolated from the BAF53 knockdown cells, the chromatin loading of H1 and core histones remained unaltered, as did the nucleosome spacing. The histone hyperacetylation and down-regulation of BRG-1, mBrm, and Tip49, the catalytic components of the SWI/SNF complex and the TIP60 complex, respectively, did not expand chromosome territories. These results indicate that BAF53 contributes to the polymeric properties and/or the internal meshwork interactions of the chromatin fiber probably via a novel mechanism.
AB - Chromosomes are compartmentalized into discrete chromosome territories during interphase in mammalian cells. A chromosome territory is generated by the tendency of chromatin to occupy the smallest shell volume, which is determined by the polymeric properties and interactions of the internal meshwork of the chromatin fiber. Here, we show that BAF53 knockdown by small interfering RNA interference led to the expansion of chromosome territories. This was accompanied by a reduction in chromatin compaction, an increase in the micrococcal nuclease sensitivity of the chromatin, and an alteration in H3-K9 and H3-K79 dimethylation. Interestingly, the BAF53 knockdown cells suffer a cell cycle defect. Despite the significant irregularity and decompaction of the polynucleosomes isolated from the BAF53 knockdown cells, the chromatin loading of H1 and core histones remained unaltered, as did the nucleosome spacing. The histone hyperacetylation and down-regulation of BRG-1, mBrm, and Tip49, the catalytic components of the SWI/SNF complex and the TIP60 complex, respectively, did not expand chromosome territories. These results indicate that BAF53 contributes to the polymeric properties and/or the internal meshwork interactions of the chromatin fiber probably via a novel mechanism.
UR - http://www.scopus.com/inward/record.url?scp=34948812424&partnerID=8YFLogxK
U2 - 10.1091/mbc.E07-05-0437
DO - 10.1091/mbc.E07-05-0437
M3 - Article
C2 - 17652455
AN - SCOPUS:34948812424
SN - 1059-1524
VL - 18
SP - 4013
EP - 4023
JO - Molecular Biology of the Cell
JF - Molecular Biology of the Cell
IS - 10
ER -