Communication between distantly spaced genomic regions is one of the key features of gene regulation in eukaryotes. Chromatin per se can stimulate efficient enhancer-promoter communication (EPC); however, the role of chromatin structure and dynamics in this process remains poorly understood. Here we show that nucleosome spacing and the presence of nucleosome-free DNA regions can modulate chromatin structure/dynamics and, in turn, affect the rate of EPC in vitro and in silico. Increasing the length of internucleosomal linker DNA from 25 to 60 bp results in more efficient EPC. The presence of longer nucleosome-free DNA regions can positively or negatively affect the rate of EPC, depending upon the length and location of the DNA region within the chromatin fiber. Thus the presence of histone-free DNA regions can differentially affect the efficiency of EPC, suggesting that gene regulation over a distance could be modulated by changes in the length of internucleosomal DNA spacers.
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http://dx.doi.org/10.1093/nar/gkw1240 | DOI Listing |
iScience
January 2025
Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA.
The regulation of gene expression relies on the coordinated action of transcription factors (TFs) at enhancers, including both activator and repressor TFs. We employed deep learning (DL) to dissect HepG2 enhancers into positive (PAR), negative (NAR), and neutral activity regions. Sharpr-MPRA and STARR-seq highlight the dichotomy impact of NARs and PARs on modulating and catalyzing the activity of enhancers, respectively.
View Article and Find Full Text PDFHealth Sci Rep
January 2025
Medical Oncology Healthcare Global Bangalore India.
Background And Aims: Sensitivity to immune checkpoint inhibitor (ICI) therapy depends in part on the genetic and epigenetic makeup of cancer cells, and CD8 T-lymphocytes that mediate immune responses. Epigenetics are heritable reversible changes in gene expression that occur without any changes in the nuclear DNA sequence or DNA copy number.
Primary Objective: i.
Parasite Epidemiol Control
February 2025
Veterinary Medicine and Animal Production Department, Naples University, 8 Via Mezzocannone, 80138 Naples, Italy.
The beech marten () is a small-size mustelid endangered according to the IUCN Red List. Despite the plethora of parasites potentially affecting its population decline, subcutaneous filarioids are occasionally reported in martens and their competent arthropod vectors are to date unknown. Therefore, from January 2023 to August 2024, this study investigated the presence of subcutaneous filarioids and ectoparasites of road-killed beech martens ( = 7) from southwestern Italy.
View Article and Find Full Text PDFData Brief
February 2025
Marine Research Institute, Klaipėda University, H. Manto 84, 92294 Klaipėda, Lithuania.
Over the last few decades, climate change in Svalbard (European Arctic) has led to the emergence and growth of periglacial coastal lagoons in the place of retreating glaciers. In these emerging water bodies, new ecosystems are formed, consisting of elements presumably entering the lagoon from the melting glacier, the surrounding tundra water bodies and the coastal ocean. The data presented here were collected from an emerging lagoon in the western region of Spitsbergen, Svalbard, situated between the retreating Eidembreen Glacier and Eidembukta Bay in 2022-2023.
View Article and Find Full Text PDFCharacterization of tumor epigenetic aberrations is integral to understanding the mechanisms of tumorigenesis and provide diagnostic, prognostic, and predictive information of high clinical relevance. Among the different tumor-associated epigenetic signatures, 5 methyl-cytosine (5mC) and 5-hydroxymethylcytosine (5hmC) are the two most well-characterized DNA methylation alterations linked to cancer pathogenesis. 5hmC has a tissue-specific distribution and its abundance is subjected to changes in tumor DNA, making it a promising biomarker.
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