Transcription factors control cell-specific gene expression programs through interactions with diverse coactivators and the transcription apparatus. Gene activation may involve DNA loop formation between enhancer-bound transcription factors and the transcription apparatus at the core promoter, but this process is not well understood. Here we report that mediator and cohesin physically and functionally connect the enhancers and core promoters of active genes in murine embryonic stem cells. Mediator, a transcriptional coactivator, forms a complex with cohesin, which can form rings that connect two DNA segments. The cohesin-loading factor Nipbl is associated with mediator-cohesin complexes, providing a means to load cohesin at promoters. DNA looping is observed between the enhancers and promoters occupied by mediator and cohesin. Mediator and cohesin co-occupy different promoters in different cells, thus generating cell-type-specific DNA loops linked to the gene expression program of each cell.
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http://dx.doi.org/10.1038/nature09380 | 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 PDFEMBO J
January 2025
Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030, Vienna, Austria.
Dev Cell
December 2024
Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA. Electronic address:
The cohesin complex is critical for genome organization and regulation, relying on specialized co-factors to mediate its diverse functional activities. Here, by analyzing patterns of similar gene requirements across cell lines, we identify PRR12 as a mediator of cohesin and genome integrity. We show that PRR12 interacts with NIPBL/MAU2 and the cohesin complex, and that the loss of PRR12 results in reduced cohesin localization and a substantial increase in DNA double-strand breaks in mouse NIH-3T3 cells.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
School of Advanced Agriculture Sciences and School of Life Sciences, Academy for Advanced Interdisciplinary Studies, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China.
In eukaryotes, chromatin is compacted within nuclei under the principle of compartmentalization. On top of that, condensin II establishes eukaryotic chromosome territories, while cohesin organizes the vertebrate genome by extruding chromatin loops and forming topologically associating domains (TADs). Thus far, the formation and roles of these chromatin structures in plants remain poorly understood.
View Article and Find Full Text PDFMol Cell
December 2024
Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA. Electronic address:
How specific enhancer-promoter pairing is established remains mostly unclear. Besides the CTCF/cohesin machinery, few nuclear factors have been studied for a direct role in physically connecting regulatory elements. Using a murine erythroid cell model, we show via acute degradation experiments that LDB1 directly and broadly promotes connectivity among regulatory elements.
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