TY - JOUR
T1 - DNA bridging and looping by HMO1 provides a mechanism for stabilizing nucleosome-free chromatin
AU - Murugesapillai, Divakaran
AU - McCauley, Micah J.
AU - Huo, Ran
AU - Holte, Molly H.Nelson
AU - Stepanyants, Armen
AU - Maher, L. James
AU - Israeloff, Nathan E.
AU - Williams, Mark C.
N1 - Funding Information:
National Institutes of Health [R01GM72462 to M.C.W.; R01GM075965 to L.J.M.; R01NS063494 to A.S.]; Mayo Foundation. Funding for open access charge: National Institutes of Health. Conflict of interest statement. None declared.
PY - 2014/8/18
Y1 - 2014/8/18
N2 - The regulation of chromatin structure in eukaryotic cells involves abundant architectural factors such as high mobility group B (HMGB) proteins. It is not understood how these factors control the interplay between genome accessibility and compaction. In vivo, HMO1 binds the promoter and coding regions of most ribosomal RNA genes, facilitating transcription and possibly stabilizing chromatin in the absence of histones. To understand how HMO1 performs these functions, we combine single molecule stretching and atomic force microscopy (AFM). By stretching HMO1-bound DNA, we demonstrate a hierarchical organization of interactions, in which HMO1 initially compacts DNA on a timescale of seconds, followed by bridge formation and stabilization of DNA loops on a timescale of minutes. AFM experiments demonstrate DNA bridging between strands as well as looping by HMO1. Our results support a model in which HMO1 maintains the stability of nucleosome-free chromatin regions by forming complex and dynamic DNA structures mediated by protein-protein interactions.
AB - The regulation of chromatin structure in eukaryotic cells involves abundant architectural factors such as high mobility group B (HMGB) proteins. It is not understood how these factors control the interplay between genome accessibility and compaction. In vivo, HMO1 binds the promoter and coding regions of most ribosomal RNA genes, facilitating transcription and possibly stabilizing chromatin in the absence of histones. To understand how HMO1 performs these functions, we combine single molecule stretching and atomic force microscopy (AFM). By stretching HMO1-bound DNA, we demonstrate a hierarchical organization of interactions, in which HMO1 initially compacts DNA on a timescale of seconds, followed by bridge formation and stabilization of DNA loops on a timescale of minutes. AFM experiments demonstrate DNA bridging between strands as well as looping by HMO1. Our results support a model in which HMO1 maintains the stability of nucleosome-free chromatin regions by forming complex and dynamic DNA structures mediated by protein-protein interactions.
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U2 - 10.1093/nar/gku635
DO - 10.1093/nar/gku635
M3 - Article
C2 - 25063301
AN - SCOPUS:84906246262
SN - 0305-1048
VL - 42
SP - 8996
EP - 9004
JO - Nucleic acids research
JF - Nucleic acids research
IS - 14
ER -