In order to efficiently edit eukaryotic genomes, it is critical to test the impact of chromatin dynamics on CRISPR/Cas9 function and develop strategies to adapt the system to eukaryotic contexts. So far, research has extensively characterized the relationship between the CRISPR endonuclease Cas9 and the composition of the RNA-DNA duplex that mediates the system's precision. Evidence suggests that chromatin modifications and DNA packaging can block eukaryotic genome editing by custom-built DNA endonucleases like Cas9; however, the underlying mechanism of Cas9 inhibition is unclear. Here, we demonstrate that closed, gene-silencing-associated chromatin is a mechanism for the interference of Cas9-mediated DNA editing. Our assays use a transgenic cell line with a drug-inducible switch to control chromatin states (open and closed) at a single genomic locus. We show that closed chromatin inhibits binding and editing at specific target sites and that artificial reversal of the silenced state restores editing efficiency. These results provide new insights to improve Cas9-mediated editing in human and other mammalian cells.
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http://dx.doi.org/10.1021/acssynbio.5b00299 | DOI Listing |
Commun Biol
January 2025
State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China.
Uncoupling protein 1 (UCP1) is a crucial protein located in the mitochondrial inner membrane that mediates nonshivering thermogenesis. However, the molecular mechanisms by which enhancer-promoter chromatin interactions control Ucp1 transcriptional regulation in brown adipose tissue (BAT) are unclear. Here, we employed circularized chromosome conformation capture coupled with next-generation sequencing (4C-seq) to generate high-resolution chromatin interaction profiles of Ucp1 in interscapular brown adipose tissue (iBAT) and epididymal white adipose tissue (eWAT) and revealed marked changes in Ucp1 chromatin interaction between iBAT and eWAT.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt.
Yttrium oxide nanoparticles (YONPs) have emerged as a promising avenue for cancer therapy, primarily due to their distinctive properties that facilitate selective targeting of cancer cells. Despite their potential, the therapeutic effects of YONPs on human epidermoid skin cancer remain largely unexplored. This study was thus conducted to investigate the impact of YONPs on both human skin normal and cancer cells, with an emphasis on assessing their cytotoxicity, genotoxicity, and the mechanisms underlying these effects.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China.
Purpose: Protein arginine methyltransferase 1 (PRMT1) is an integral constituent of numerous cellular processes. However, its role in corneal epithelial wound healing (CEWH) remains unclear. This study investigates the impact of PRMT1 on cellular mechanisms underlying corneal epithelial repair and its potential to improve wound healing outcomes.
View Article and Find Full Text PDFJ Chem Phys
January 2025
CNRS, Laboratoire PHENIX (Physicochimie des Electrolytes et Nanosystèmes Interfaciaux), Sorbonne Université, 4 Place Jussieu, 75005 Paris, France.
By means of a minimal physical model, we investigate the interplay of two phase transitions at play in chromatin organization: (1) liquid-liquid phase separation within the fluid solvating chromatin, resulting in the formation of biocondensates; and (2) the coil-globule crossover of the chromatin fiber, which drives the condensation or extension of the chain. In our model, a species representing a domain of chromatin is embedded in a binary fluid. This fluid phase separates to form a droplet rich in a macromolecule (B).
View Article and Find Full Text PDFNature
January 2025
Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
The abundance and sequence of satellite DNA at and around centromeres is evolving rapidly despite the highly conserved and essential process through which the centromere directs chromosome inheritance. The impact of such rapid evolution is unclear. Here we find that sequence-dependent DNA shape dictates packaging of pericentromeric satellites in female meiosis through a conserved DNA-shape-recognizing chromatin architectural protein, high mobility group AT-hook 1 (HMGA1).
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