Independence of Repressive Histone Marks and Chromatin Compaction during Senescent Heterochromatic Layer Formation

Chandra, T., Kirschner, K., Thuret, J., Pope, B. D., Ryba, T., Newman, S., Ahmed, K., Samarajiwa, S. A., Salama, R., Carroll, T., Stark, R., Janky, R., Narita, M., Xue, L., Chicas, A., Nũnez, S., Janknecht, Ralf, Hayashi-Takanaka, Y., Wilson, M. D., Marshall, A., Odom, D. T, Babu, M.  M., Bazett-Jones, D. P., Tavaré, S., Edwards, P. A. W., Lowe, S. W., Kimura, H., Gilbert, D. M., Narita, M. (2012) Independence of Repressive Histone Marks and Chromatin Compaction during Senescent Heterochromatic Layer Formation. Molecular Cell, 47 (2). pp. 203-214. ISSN 1097-2765

Abstract

Summary The expansion of repressive epigenetic marks has been implicated in heterochromatin formation during embryonic development, but the general applicability of this mechanism is unclear. Here we show that nuclear rearrangement of repressive histone marks H3K9me3 and H3K27me3 into nonoverlapping structural layers characterizes senescence-associated heterochromatic foci (SAHF) formation in human fibroblasts. However, the global landscape of these repressive marks remains unchanged upon SAHF formation, suggesting that in somatic cells, heterochromatin can be formed through the spatial repositioning of pre-existing repressively marked histones. This model is reinforced by the correlation of presenescent replication timing with both the subsequent layered structure of SAHFs and the global landscape of the repressive marks, allowing us to integrate microscopic and genomic information. Furthermore, modulation of SAHF structure does not affect the occupancy of these repressive marks, nor vice versa. These experiments reveal that high-order heterochromatin formation and epigenetic remodeling of the genome can be discrete events.

Item Type: Paper
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > histone
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types
CSHL Authors:
Communities: CSHL labs > Lowe lab
Depositing User: Matt Covey
Date: 2012
Date Deposited: 31 Jan 2013 19:59
Last Modified: 19 Jul 2021 20:21
PMCID: PMC3701408
Related URLs:
URI: https://repository.cshl.edu/id/eprint/26919

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