Transcription factor access to regulatory elements is prevented by the nucleosome. Heat shock factor 1 (HSF1) is a winged helix transcription factor that plays roles in control and stressed conditions by gaining access to target elements, but mechanisms of HSF1 access are not well known in mammalian cells. Here, we show the physical interaction between the wing motif of human HSF1 and replication protein A (RPA), which is involved in DNA metabolism. Depletion of RPA1 abolishes HSF1 access to the promoter of HSP70 in unstressed condition and delays its rapid activation in response to heat shock. The HSF1-RPA complex leads to preloading of RNA polymerase II and opens the chromatin structure by recruiting a histone chaperone, FACT. Furthermore, this interaction is required for melanoma cell proliferation. These results provide a mechanism of constitutive HSF1 access to nucleosomal DNA, which is important for both basal and inducible gene expression.
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http://dx.doi.org/10.1016/j.molcel.2012.07.026 | DOI Listing |
bioRxiv
November 2024
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA.
Protein mutational landscapes are sculpted by the impacts of the resulting amino acid substitutions on the protein's stability and folding or aggregation kinetics. These properties can, in turn, be modulated by the composition and activities of the cellular proteostasis network. Heat shock factor 1 (HSF1) is the master regulator of the cytosolic and nuclear proteostasis networks, dynamically tuning the expression of cytosolic and nuclear chaperones and quality control factors to meet demand.
View Article and Find Full Text PDFInt J Biometeorol
November 2024
Rajiv Gandhi Institute of Veterinary Education and Research, Kurumbapet, Puducherry, 605009, India.
The general objective of this study is to comparatively assess the climate-resilient potential of four different poultry genotypes-Giriraja (n = 8), Country chicken (n = 8), Naked neck (n = 8), and Kadaknath (n = 8)-reared in a hot-humid tropical environment. Birds from all genotypes had ad libitum access to feed and water and were exposed to identical environmental temperatures in the experimental shed. Diurnal meteorological data were recorded inside and outside the shed daily.
View Article and Find Full Text PDFBr J Cancer
September 2024
College of Public Health, Zhengzhou University, Zhengzhou, 450001, Henan Provinc, China.
Background: Esophageal squamous cell carcinoma (ESCC) is a deadly cancer with no clinically ideal biomarkers for early diagnosis. The objective of this study was to develop and validate a user-friendly diagnostic tool for early ESCC detection.
Methods: The study encompassed three phases: discovery, verification, and validation, comprising a total of 1309 individuals.
Cancer Rep (Hoboken)
June 2024
Drug Development Unit, Royal Marsden Hospital/Institute of Cancer Research, Sutton, UK.
Arterioscler Thromb Vasc Biol
June 2024
A.I. Virtanen Institute for Molecular Sciences (I.S., M.K., T.Ö., K.Õ., M.G., A.R., K.M., A.T., J.P.L., M.U.K.), University of Eastern Finland, Kuopio.
Background: CALCRL (calcitonin receptor-like) protein is an important mediator of the endothelial fluid shear stress response, which is associated with the genetic risk of coronary artery disease. In this study, we functionally characterized the noncoding regulatory elements carrying coronary artery disease that risks single-nucleotide polymorphisms and studied their role in the regulation of expression in endothelial cells.
Methods: To functionally characterize the coronary artery disease single-nucleotide polymorphisms harbored around the gene , we applied an integrative approach encompassing statistical, transcriptional (RNA-seq), and epigenetic (ATAC-seq [transposase-accessible chromatin with sequencing], chromatin immunoprecipitation assay-quantitative polymerase chain reaction, and electromobility shift assay) analyses, alongside luciferase reporter assays, and targeted gene and enhancer perturbations (siRNA and clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated 9) in human aortic endothelial cells.
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