The effect of chromatin non-histone protein on DNA and chromatin stability is investigated by differential thermal denaturation method. 1) Chromatin (rat liver) yields a multiphasic melting profile. The major part of the melting curve of this chromatin is situated at temperatures higher than pure DNA, with a distinct contribution due to nucleosomes melting. A minor part melts at temperatures lower than DNA which may be assigned to chromatin non-histone protein-DNA complex which destabilized DNA structure. 2) Heparin which extracts histones lowers the melting profile of chromatin and one observes also a contribution with a Tm lower that of pure DNA. In contrast, extraction on non-histone proteins by urea supresses the low Tm peak. 3) Reconstitution of chromatin non-histone protein-DNA complexes confirms the existence of a fraction of chromatin non-histone protein which lowers the melting temperature when compared to pure DNA. It is concluded that chromatin non-histone proteins contain different fractions of proteins which are causing stabilizing and destabilizing effect on DNA structure.
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http://dx.doi.org/10.1093/nar/4.7.2293 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, Valencia 46022, Spain.
The SWItch/Sucrose Non-Fermenting (SWI/SNF) complexes are evolutionarily conserved, ATP-dependent chromatin remodelers crucial for multiple nuclear functions in eukaryotes. Recently, plant BCL-DOMAIN HOMOLOG (BDH) proteins were identified as shared subunits of all plant SWI/SNF complexes, significantly impacting chromatin accessibility and various developmental processes in Arabidopsis. In this study, we performed a comprehensive characterization of mutants, revealing the role of BDH in hypocotyl cell elongation.
View Article and Find Full Text PDFNat Commun
January 2025
Shanghai Immune Therapy Institute, Shanghai Jiao Tong University School of Medicine- Affiliated Renji Hospital, Shanghai, 200127, China.
T cell activation is accompanied by extensive changes in epigenome. However, the high-ordered chromatin organization underpinning CD8 T cell activation is not fully known. Here, we show extensive changes in the three-dimensional genome during CD8 T cell activation, associated with changes in gene transcription.
View Article and Find Full Text PDFNat Commun
January 2025
Infinity, Toulouse Institute for Infectious and Inflammatory Diseases, University of Toulouse, Inserm U1291, CNRS U5051, Toulouse, France.
Protective immune responses require close interactions between conventional (Tconv) and regulatory T cells (Treg). The extracellular mediators and signaling events that regulate the crosstalk between these CD4 T cell subsets have been extensively characterized. However, how Tconv translate Treg-dependent suppressive signals at the chromatin level remains largely unknown.
View Article and Find Full Text PDFJ Cell Biol
March 2025
Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL) , Heidelberg, Germany.
How cells establish the interphase genome organization after mitosis is incompletely understood. Using quantitative and super-resolution microscopy, we show that the transition from a Condensin to a Cohesin-based genome organization occurs dynamically over 2 h. While a significant fraction of Condensins remains chromatin-bound until early G1, Cohesin-STAG1 and its boundary factor CTCF are rapidly imported into daughter nuclei in telophase, immediately bind chromosomes as individual complexes, and are sufficient to build the first interphase TAD structures.
View Article and Find Full Text PDFClin Rev Allergy Immunol
December 2024
Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, People's Republic of China.
The switch/sucrose non-fermentable (SWI/SNF) chromatin remodeling complexes (also referred to as BAF complexes) are composed of multiple subunits, which regulate the nucleosome translocation and chromatin accessibility. In recent years, significant advancements have been made in understanding mutated genes encoding subunits of the SWI/SNF complexes in cancer biology. Nevertheless, the role of SWI/SNF complexes in immune response and inflammatory diseases continues to attract significant attention.
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