Constitutive heterochromatin is a compact, transcriptionally inert structure formed in gene-poor and repeat- and transposon-rich regions. In Arabidopsis, constitutive heterochromatin is characterized by hypermethylated DNA and histone H3 dimethylated at lysine (K) 9 (H3K9me2) together with depletion of histone H3 dimethylated at lysine 4 (H3K4me2). Here, we describe loci with intermediate properties of heterochromatin in which transcription downregulation is inherited in a manner similar to constitutive heterochromatin, although the loci are associated with opposing histone marks--H3K4me2 and H3K9me2. In the ddm1 (decrease in DNA methylation 1) mutants, their transcriptional activation is accompanied by the expected shift in the H3 modifications--depletion of H3K9me2 and enrichment in H3K4me2. In mom1 (Morpheus' molecule 1) mutants, however, a marked increase in transcription is not accompanied by detectable changes in the levels of H3K4me2 and H3K9me2. Therefore, transcriptional regulation in the intermediate heterochromatin involves two distinct epigenetic mechanisms. Interestingly, silent transgenic inserts seem to acquire properties characteristic of the intermediate heterochromatin.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1794695 | PMC |
| http://dx.doi.org/10.1038/sj.embor.7400835 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Tau mediates the reshaping of the transcriptional landscape toward intermediate Alzheimer's disease stages.
Front Cell Dev Biol
January 2025
Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, Pisa, Italy.
Introduction: Recent research revealed that Tau plays critical roles in various neuronal functions. We previously demonstrated that destabilization and nuclear delocalization of Tau alter the expression of glutamatergic genes, mediating early neuronal damage.
Methods: In this study, we discovered that changes in Tau availability are linked to global alterations in gene expression that affect multiple neuronal pathways.
How the Oocyte Nucleolus Is Turned into a Karyosphere: The Role of Heterochromatin and Structural Proteins.
J Dev Biol
October 2024
Medical Faculty, Department of Biology, Medical University of Sofia, 1431 Sofia, Bulgaria.
Oocyte meiotic maturation includes large-scale chromatin remodeling as well as cytoskeleton and nuclear envelope rearrangements. This review addresses the dynamics of key cytoskeletal proteins (tubulin, actin, vimentin, and cytokeratins) and nuclear envelope proteins (lamin A/C, lamin B, and the nucleoporin Nup160) in parallel with chromatin reorganization in maturing mouse oocytes. A major feature of this reorganization is the concentration of heterochromatin into a spherical perinucleolar rim called surrounded nucleolus or karyosphere.
View Article and Find Full Text PDFInvestigating Different Dynamic pHP1α States in Their KCl-Mediated Liquid-Liquid Phase Separation (LLPS) Using Solid-State NMR (SSNMR) and Molecular Dynamic (MD) Simulations.
J Phys Chem B
October 2024
Centre of High Field NMR Spectroscopy and Imaging, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore.
Article Synopsis
- Chromatin phase separation is influenced by factors like post-translational modifications and plays a key role in genomic functions, but the exact mechanisms are still not well understood.
- The study utilized modified solid-state NMR techniques to investigate dynamic components in phosphorylated heterochromatin protein 1α (pHP1α) and found that different NMR methods can provide insights into molecular dynamics within phase-separated systems.
- Results showed that lower KCl concentrations (30 mM) reduced molecular motion in the protein gel, whereas higher concentrations (150 mM) increased motion due to changes in intermolecular electrostatic interactions.
H3K9me3 loss and ERVs activation as hallmarks for osteoarthritis progression and knee joint aging.
Osteoarthritis Cartilage
January 2025
Department of Cell Biology, Van Andel Institute, Grand Rapids, MI 49503, USA. Electronic address:
Objective: This study aims to link aberrant endogenous retroviruses (ERVs) activation and osteoarthritis (OA) progression by comparing the chromatin accessibility and transcriptomic landscapes of diseased or intact joint tissues of OA patients.
Method: We performed ERVs-centric analysis on published ATAC-seq and RNA-seq data from OA patients' cartilage tissues. Here, we compared the outer region of the lateral tibial plateau, representing intact cartilage, to the inner region of the medial tibial plateau, representing damaged cartilage.
Unraveling the association between major depressive disorder and senescent biomarkers in immune cells of older adults: a single-cell phenotypic analysis.
Front Aging
April 2024
UConn Health Center on Aging, University of Connecticut School of Medicine, Farmington, CT, United States.
Little is known about the prevalence of cellular senescence among immune cells (i.e., immune cells expressing senescence markers, iSCs) nor is there a gold-standard to efficiently measure iSCs.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!