An RNA polymerase II promoter has been isolated in transcriptionally activated and repressed states. Topological and nuclease digestion analyses have revealed a dynamic equilibrium between nucleosome removal and reassembly upon transcriptional activation, and have further shown that nucleosomes are removed by eviction of histone octamers rather than by sliding. The promoter, once exposed, assembles with RNA polymerase II, general transcription factors, and Mediator in a approximately 3 MDa transcription initiation complex. X-ray crystallography has revealed the structure of RNA polymerase II, in the act of transcription, at atomic resolution. Extension of this analysis has shown how nucleotides undergo selection, polymerization, and eventual release from the transcribing complex. X-ray and electron crystallography have led to a picture of the entire transcription initiation complex, elucidating the mechanisms of promoter recognition, DNA unwinding, abortive initiation, and promoter escape.
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http://dx.doi.org/10.1016/j.febslet.2004.11.027 | DOI Listing |
Invest Ophthalmol Vis Sci
January 2025
Institute of Ophthalmology, School of Medicine, Jinan University, Guangzhou, China.
Purpose: To investigate the therapeutic efficacy of BEZ235, a dual PI3K/mTOR inhibitor, in suppressing pathological neovascularization in an oxygen-induced retinopathy (OIR) mouse model and explore the role of cyclin D1 in endothelial cell cycle regulation.
Methods: Single-cell RNA sequencing was performed to analyze gene expression and cell-cycle alterations in retinal endothelial cells under normoxic and OIR conditions. The effects of BEZ235 on human umbilical vein endothelial cells (HUVECs) and human retinal microvascular endothelial cells (HRMECs) were evaluated by assessing cell viability, cell-cycle progression, proliferation, migration, and tube formation.
Microbiol Spectr
January 2025
Department of Virology, Pontchaillou University Hospital, Rennes, France.
We report a case of wild-type rubella virus (genotype 2B) granuloma in a 29-year-old immunocompromised patient with a full vaccination scheme. He had been followed since his early teens for an unlabeled systemic inflammatory disease. On an inguinal node biopsy, histological analysis revealed a nguudiffuse non-necrotic granulomatous inflammation with no identified conventional infectious agent involved in granuloma formation.
View Article and Find Full Text PDFClin Pharmacol Ther
January 2025
Gilead Sciences, Inc., Foster City, California, USA.
Obeldesivir is an oral nucleoside analog prodrug inhibitor of SARS-CoV-2 RNA-dependent RNA polymerase and other viral polymerases. Here, two Phase I studies evaluated potential drug-drug interactions between obeldesivir and substrates or inhibitors of cytochrome P450 and drug transporters in healthy participants. When obeldesivir was tested as a precipitant, pharmacokinetic parameter point estimates for midazolam (CYP3A4 inhibition/induction), caffeine (CYP1A2 inhibition), and metformin (organic cation transporter 1 inhibition) exposures were within 80-125% no-effect bounds representing the interval within which a systemic exposure change does not warrant clinical action based on EMA/FDA guidance.
View Article and Find Full Text PDFJ Med Microbiol
January 2025
Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, Merseyside, L3 5QA, UK.
Immediate identification of travellers' diarrhoea-causing pathogens may not be possible in remote settings, but samples can be stored for epidemiological and related research. We collected pilot data to evaluate the utility of three different preservation media for testing stored faecal samples compared to immediate testing of fresh samples using the BioFire FilmArray multiplex PCR gastrointestinal panel (bioMérieux). No previous studies have demonstrated the utility of testing faecal samples directly by PCR BioFire FilmArray following prolonged storage and transportation in OMNIgene, DNA shield and FTA cards.
View Article and Find Full Text PDFBr Poult Sci
January 2025
College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China.
1. As one of the most widespread poultry species in the world, pigeons have been bred primarily for meat production due to their high nutritional value and good taste. Their breast muscle is an important economic product as it determines the yield and quality of meat from pigeons.
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