Constitutive heterochromatin controls nuclear mechanics, morphology, and integrity through H3K9me3 mediated chromocenter compaction

Aberrant nuclear morphology is a hallmark of human disease and causes nuclear dysfunction. Perturbed nuclear mechanics via reduced heterochromatin weakens the nucleus resulting in nuclear blebbing and rupture. While the role of heterochromatin is known, the separate roles of constitutive heterochrom...

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Main Authors: Gianna Manning, Andy Li, Nebiyat Eskndir, Marilena Currey, Andrew D. Stephens
Format: Article
Language:English
Published: Taylor & Francis Group 2025-12-01
Series:Nucleus
Subjects:
Online Access:https://www.tandfonline.com/doi/10.1080/19491034.2025.2486816
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author Gianna Manning
Andy Li
Nebiyat Eskndir
Marilena Currey
Andrew D. Stephens
author_facet Gianna Manning
Andy Li
Nebiyat Eskndir
Marilena Currey
Andrew D. Stephens
author_sort Gianna Manning
collection DOAJ
description Aberrant nuclear morphology is a hallmark of human disease and causes nuclear dysfunction. Perturbed nuclear mechanics via reduced heterochromatin weakens the nucleus resulting in nuclear blebbing and rupture. While the role of heterochromatin is known, the separate roles of constitutive heterochromatin methylation states remains elusive. Using MEF and HT1080 cells, we isolated the individual contribution of constitutive heterochromatin H3K9 methylation states through histone methyltransferase inhibitors. Inhibition of SUV39H1 via Chaetocin downregulates H3K9 trimethylation (me3), while inhibition of G9a via BIX01294 downregulates H3K9 dimethylation (me2). Overall, the loss of H3K9me3 increased nuclear blebbing and rupture in interphase nuclei due to decreased nuclear rigidity from decompaction of chromocenters. Oppositely, loss of H3K9me2 decreased nuclear blebbing and rupture with increased nuclear rigidity and more compact chromocenters. We show that facultative heterochromatin and HP1α are non-essential for chromocenter compaction. Constitutive heterochromatin provides essential nuclear mechanical support to maintain nuclear shape and integrity through chromocenter compaction.
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spelling doaj-art-f315e5c882ca441fa8432d80ca92c5562025-08-20T03:08:36ZengTaylor & Francis GroupNucleus1949-10341949-10422025-12-0116110.1080/19491034.2025.2486816Constitutive heterochromatin controls nuclear mechanics, morphology, and integrity through H3K9me3 mediated chromocenter compactionGianna Manning0Andy Li1Nebiyat Eskndir2Marilena Currey3Andrew D. Stephens4Biology Department, University of Massachusetts Amherst, Amherst, MA, USABiology Department, University of Massachusetts Amherst, Amherst, MA, USABiology Department, University of Massachusetts Amherst, Amherst, MA, USABiology Department, University of Massachusetts Amherst, Amherst, MA, USABiology Department, University of Massachusetts Amherst, Amherst, MA, USAAberrant nuclear morphology is a hallmark of human disease and causes nuclear dysfunction. Perturbed nuclear mechanics via reduced heterochromatin weakens the nucleus resulting in nuclear blebbing and rupture. While the role of heterochromatin is known, the separate roles of constitutive heterochromatin methylation states remains elusive. Using MEF and HT1080 cells, we isolated the individual contribution of constitutive heterochromatin H3K9 methylation states through histone methyltransferase inhibitors. Inhibition of SUV39H1 via Chaetocin downregulates H3K9 trimethylation (me3), while inhibition of G9a via BIX01294 downregulates H3K9 dimethylation (me2). Overall, the loss of H3K9me3 increased nuclear blebbing and rupture in interphase nuclei due to decreased nuclear rigidity from decompaction of chromocenters. Oppositely, loss of H3K9me2 decreased nuclear blebbing and rupture with increased nuclear rigidity and more compact chromocenters. We show that facultative heterochromatin and HP1α are non-essential for chromocenter compaction. Constitutive heterochromatin provides essential nuclear mechanical support to maintain nuclear shape and integrity through chromocenter compaction.https://www.tandfonline.com/doi/10.1080/19491034.2025.2486816Chromocenterheterochromatinnuclear blebbingnuclear mechanicsnuclear structure
spellingShingle Gianna Manning
Andy Li
Nebiyat Eskndir
Marilena Currey
Andrew D. Stephens
Constitutive heterochromatin controls nuclear mechanics, morphology, and integrity through H3K9me3 mediated chromocenter compaction
Nucleus
Chromocenter
heterochromatin
nuclear blebbing
nuclear mechanics
nuclear structure
title Constitutive heterochromatin controls nuclear mechanics, morphology, and integrity through H3K9me3 mediated chromocenter compaction
title_full Constitutive heterochromatin controls nuclear mechanics, morphology, and integrity through H3K9me3 mediated chromocenter compaction
title_fullStr Constitutive heterochromatin controls nuclear mechanics, morphology, and integrity through H3K9me3 mediated chromocenter compaction
title_full_unstemmed Constitutive heterochromatin controls nuclear mechanics, morphology, and integrity through H3K9me3 mediated chromocenter compaction
title_short Constitutive heterochromatin controls nuclear mechanics, morphology, and integrity through H3K9me3 mediated chromocenter compaction
title_sort constitutive heterochromatin controls nuclear mechanics morphology and integrity through h3k9me3 mediated chromocenter compaction
topic Chromocenter
heterochromatin
nuclear blebbing
nuclear mechanics
nuclear structure
url https://www.tandfonline.com/doi/10.1080/19491034.2025.2486816
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AT andyli constitutiveheterochromatincontrolsnuclearmechanicsmorphologyandintegritythroughh3k9me3mediatedchromocentercompaction
AT nebiyateskndir constitutiveheterochromatincontrolsnuclearmechanicsmorphologyandintegritythroughh3k9me3mediatedchromocentercompaction
AT marilenacurrey constitutiveheterochromatincontrolsnuclearmechanicsmorphologyandintegritythroughh3k9me3mediatedchromocentercompaction
AT andrewdstephens constitutiveheterochromatincontrolsnuclearmechanicsmorphologyandintegritythroughh3k9me3mediatedchromocentercompaction