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In animal cells, replication-dependent histone pre-mRNAs are processed at the 3'-end by an endonucleolytic cleavage carried out by the U7 snRNP, a machinery that contains the U7 snRNA and many protein subunits. Studies on the composition of this machinery and understanding of its role in 3'-end processing were greatly facilitated by the development of an in vitro system utilizing nuclear extracts from mammalian cells 35 years ago and later from Drosophila cells. Most recently, recombinant expression and purification of the components of the machinery have enabled the full reconstitution of an active machinery and its complex with a model pre-mRNA substrate, using 13 proteins and 2 RNAs, and the determination of the structure of this active machinery. This chapter presents protocols for preparing nuclear extracts containing endogenous processing machinery, for assembling semi-recombinant and fully reconstituted machineries, and for histone pre-mRNA 3'-end processing assays with these samples.
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http://dx.doi.org/10.1016/bs.mie.2021.03.021 | DOI Listing |
Cell Rep
August 2025
Curriculum in Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; McAllister Heart Institute, The University of North Carolina at Chapel H
Through mechanotransduction, cells sense and respond to mechanical stimuli from their environment. A mechanical stimulus is first detected by a mechanosensor, then converted into a biochemical signal, which can ultimately control the expression of genes. RNA processing, which includes canonical and alternative splicing, 3' end polyadenylation, and 5' end capping, is a mechanism that fine-tunes gene expression regulation.
View Article and Find Full Text PDFBrief Funct Genomics
January 2025
Department of Ultrasound Medicine, The 900th Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army, No. 156, North West Second Ring Road, Gulou District, Fuzhou, Fujian 350001, China.
The evolutionarily conserved Integrator complex, which is composed of over 10 subunits, orchestrates diverse RNA-processing events such as 3'-end maturation of small nuclear RNAs (snRNAs), transcription termination of RNA Polymerase II, and DNA damage response signaling pathways; however, the functional roles of individual Integrator complex subunits in lung adenocarcinoma (LUAD) remain poorly characterized, and this study aimed to systematically investigate the potential oncogenic functions and prognostic values of these subunits in LUAD. To achieve this goal, the expression profiles of Integrator complex subunits were profiled using transcriptomic data from the The Cancer Genome Atlas (TCGA) database, survival analyses (including Kaplan-Meier and Cox regression models) were performed to evaluate the correlations between subunit expression levels and patient survival outcomes (overall survival (OS) and disease-free survival (DFS)), co-expression network analysis was conducted to annotate the potential biological functions of key subunits, and functional validation was performed using CCK-8 assays and flow cytometry to assess the impact of INTS7 depletion on cell proliferation and cycle progression in LUAD cell lines. The findings of this study showed that Integrator complex subunits were significantly overexpressed in LUAD tissues compared to normal lung parenchyma; among these subunits, INTS7 expression was most strongly associated with shortened OS and DFS, indicating its pivotal role in LUAD pathogenesis, while bioinformatics analyses revealed that INTS7 is involved in regulating critical biological processes including cell cycle progression, transcriptional regulation, and RNA metabolism, and loss-of-function experiments demonstrated that genetic silencing of INTS7 significantly inhibited cell proliferation and induced cell cycle arrest in LUAD cells.
View Article and Find Full Text PDFNat Commun
August 2025
College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China.
Alternative polyadenylation (APA) generates transcript diversity by producing mRNA isoforms with distinct 3' ends. Despite the critical roles that APA plays in various biological processes, the mechanisms regulating APA in response to stresses have remained poorly understood in plants. Here, we perform comprehensive analysis of APA in tomato, and focus on a phosphate (Pi)- regulated APA gene SlSPX5, encoding a putative Pi sensor protein.
View Article and Find Full Text PDFNat Commun
August 2025
Department of Life Science, Graduate School of Arts and Science, The University of Tokyo, Meguro, Tokyo, Japan.
Transfer RNA (tRNA) plays a central role in translation. The simultaneous in vitro synthesis of minimal yet sufficient tRNA species (at least 21) poses a challenge for constructing a self-reproducible artificial cell. A key obstacle is the processing of the 5' and 3' ends, which requires a multi-step reaction in the natural cells.
View Article and Find Full Text PDFSci Rep
August 2025
Laboratory of Biomolecules, Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas (UPC), 15023, Lima, Peru.
Ribosome assembly is a multistep process that ensures a functional ribosome structure. The molecular mechanism that ribosome-associated GTPases (RA-GTPases) use to enhance ribosome assembly accuracy remains largely to be elucidated. Here, we use systematic evolution of ligands by exponential enrichment (SELEX), followed by sequencing, comprehensive bioinformatics analysis, and biochemical characterization to identify aptamers that target the RA-GTPase ERA of Staphylococcus aureus.
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