Transcription initiation sites of the asparagine synthetase gene were investigated in human hepatoma cells after amino acid limitation by incubation in amino acid-complete minimal essential medium or medium lacking histidine. Cells incubated in complete minimal essential medium had mRNA transcripts with starting positions spanning across the 69 nucleotides immediately upstream of a previously designated transcription start site (+1), whereas the majority of mRNA transcripts started at nucleotide (+1) in cells incubated in histidine-free medium. Similar results were obtained regardless of whether the analysis was by 5' rapid amplification of cDNA ends or a ribonuclease protection assay. Low ASNS mRNA expression in amino acid-complete medium was associated with the wide range of initiation sites, whereas preferred alignment of the general transcription machinery at nucleotide (+1), observed in the amino acid deprived condition, was associated with a concurrent increase in transcription activity. To our knowledge, these results are the first example in a mammalian cell of transcription start selection by nutrient availability.
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http://dx.doi.org/10.1093/jn/136.10.2463 | DOI Listing |
Fam Pract
January 2025
School of Nursing and Midwifery, Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
Background: One role of primary care is to support people living with and beyond cancer, the number of whom is increasing worldwide. This study aimed to identify factors affecting cancer care provision within English primary care after the start of the coronavirus pandemic, during high healthcare service demand, and a depleted workforce.
Methods: An exploratory qualitative descriptive approach was used to collect data via remote semi-structured interviews with primary care staff after gaining informed consent.
Epigenetics Chromatin
January 2025
Clinical Big Data Research Center, Scientific Research Center, Shenzhen Key Laboratory of Bone Tissue Repair and Translational Research, The Seventh Affiliated Hospital of Sun Yat-Sen University, Shenzhen, 518107, People's Republic of China.
Background: Histone modification H3K27me3 plays a critical role in normal development and is associated with various diseases, including cancer. This modification forms large chromatin domains, known as Large Organized Chromatin Lysine Domains (LOCKs), which span several hundred kilobases.
Result: In this study, we identify and categorize H3K27me3 LOCKs in 109 normal human samples, distinguishing between long and short LOCKs.
Histochem Cell Biol
January 2025
College of Life Sciences, Key Laboratory of Animal Reproduction and Biotechnology in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China.
Skin-derived stem cells (SDSCs) are a subtype of adult stem cells (ASCs) that are widely harvested and exempt from ethical restrictions in clinical applications. These cells possess capabilities for self-renewal, proliferation, and multi-lineage differentiation. Compared to model animals like rats and mice, pigs exhibit greater physiological similarity to humans.
View Article and Find Full Text PDFRecent studies have demonstrated that the production of bidirectional enhancer-derived transcripts (eRNAs) is a characteristic of an active Cis-regulatory element (CRE). Higher levels of eRNA synthesis correlate with the activation of histone modifications, a potentially valuable tool for deciphering the complexity of the gene regulatory network. To understand the changes of CREs during gonadal development in mice, we collected gonadal WT1-positive cells from the piggyBac-Wt1-mCherry-2A-EGFP (PBWt1-RG) reporter strain at E13.
View Article and Find Full Text PDFMetabolism
January 2025
Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China; Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China. Electronic address:
Epithelial sodium channel (ENaC), located in the collecting duct principal cells of the kidney, is responsible for the reabsorption of sodium and plays a critical role in the regulation of extracellular fluid volume and consequently blood pressure. The G protein-coupled bile acid receptor (TGR5) is a membrane receptor mediating effects of bile acid and is implicated in kidney diseases. The current study aims to investigate whether TGR5 activation in the kidney regulated ENaC expression and potential mechanism.
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