title: The Actin-Related Protein BAF53 Is Essential for Chromosomal Subdomain Integrity.
abstract: A chromosome territory is composed of chromosomal subdomains. The internal structure of chromosomal subdomains provides a structural framework for many genomic activities such as replication and DNA repair, and thus is key to determining the basis of their mechanisms. However, the internal structure and regulating proteins of a chromosomal subdomain remains elusive. Previously, we showed that the chromosome territory expanded after BAF53 knockdown. Because the integrity of chromosomal subdomains is a deciding factor of the volume of a chromosome territory, we examined here the effect of BAF53 knockdown on chromosomal subdomains. We found that BAF53 knockdown led to the disintegration of histone H2B-GFP-visualized chromosomal subdomains and BrdU-labeled replication foci. In addition, the size of DNA loops measured by the maximum fluorescent halo technique increased and became irregular after BAF53 knockdown, indicating DNA loops were released from the residual nuclear structure. These data can be accounted for by the model that BAF53 is prerequisite for maintaining the structural integrity of chromosomal subdomains.
authors.affiliation: Department of Bioscience and Biotechnology and Protein Research Center for Bio-Industry, Hankuk University of Foreign Studies, Yongin 449-791, Korea.
authors.forename: Kiwon
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Bioscience and Biotechnology and Protein Research Center for Bio-Industry, Hankuk University of Foreign Studies, Yongin 449-791, Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Bioscience and Biotechnology and Protein Research Center for Bio-Industry, Hankuk University of Foreign Studies, Yongin 449-791, Korea.
authors.forename: Hyockman
authors.initials: H
authors.lastname: Kwon
mesh_terms: D000199:Actins / Q000502:physiology*; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D043171:Chromosomal Instability; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology*; D002877:Chromosomes, Human / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000502:physiology*; D059585:G1 Phase Cell Cycle Checkpoints; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells
chemical_list: C116160:ACTL6A protein, human; D000199:Actins; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins
keywords: BAF53; DNA loop; actin-related protein; chromosomal subdomain; replication foci