1
|
Neumann H, Bartle L, Bonnell E, Wellinger RJ. Ratcheted transport and sequential assembly of the yeast telomerase RNP. Cell Rep 2023; 42:113565. [PMID: 38096049 DOI: 10.1016/j.celrep.2023.113565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 10/04/2023] [Accepted: 11/22/2023] [Indexed: 12/30/2023] Open
Abstract
The telomerase ribonucleoprotein particle (RNP) replenishes telomeric DNA and minimally requires an RNA component and a catalytic protein subunit. However, telomerase RNP maturation is an intricate process occurring in several subcellular compartments and is incompletely understood. Here, we report how the co-transcriptional association of key telomerase components and nuclear export factors leads to an export-competent, but inactive, RNP. Export is dependent on the 5' cap, the 3' extension of unprocessed telomerase RNA, and protein associations. When the RNP reaches the cytoplasm, an extensive protein swap occurs, the RNA is trimmed to its mature length, and the essential catalytic Est2 protein joins the RNP. This mature and active complex is then reimported into the nucleus as its final destination and last processing steps. The irreversible processing events on the RNA thus support a ratchet-type model of telomerase maturation, with only a single nucleo-cytoplasmic cycle that is essential for the assembly of mature telomerase.
Collapse
Affiliation(s)
- Hannah Neumann
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3201 Rue Jean Mignault, Sherbrooke, QC J1E 4K8, Canada
| | - Louise Bartle
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3201 Rue Jean Mignault, Sherbrooke, QC J1E 4K8, Canada; Research Center on Aging (CdRV), 1036 rue Belvedere Sud, Sherbrooke, QC J1H 4C4, Canada
| | - Erin Bonnell
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3201 Rue Jean Mignault, Sherbrooke, QC J1E 4K8, Canada
| | - Raymund J Wellinger
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3201 Rue Jean Mignault, Sherbrooke, QC J1E 4K8, Canada; Research Center on Aging (CdRV), 1036 rue Belvedere Sud, Sherbrooke, QC J1H 4C4, Canada.
| |
Collapse
|
2
|
Thompson MK, Ceccarelli A, Ish-Horowicz D, Davis I. Dynamically regulated transcription factors are encoded by highly unstable mRNAs in the Drosophila larval brain. RNA (NEW YORK, N.Y.) 2023; 29:1020-1032. [PMID: 37041032 DOI: 10.1261/rna.079552.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 03/14/2023] [Indexed: 06/18/2023]
Abstract
The level of each RNA species depends on the balance between its rates of production and decay. Although previous studies have measured RNA decay across the genome in tissue culture and single-celled organisms, few experiments have been performed in intact complex tissues and organs. It is therefore unclear whether the determinants of RNA decay found in cultured cells are preserved in an intact tissue, and whether they differ between neighboring cell types and are regulated during development. To address these questions, we measured RNA synthesis and decay rates genome wide via metabolic labeling of whole cultured Drosophila larval brains using 4-thiouridine. Our analysis revealed that decay rates span a range of more than 100-fold, and that RNA stability is linked to gene function, with mRNAs encoding transcription factors being much less stable than mRNAs involved in core metabolic functions. Surprisingly, among transcription factor mRNAs there was a clear demarcation between more widely used transcription factors and those that are expressed only transiently during development. mRNAs encoding transient transcription factors are among the least stable in the brain. These mRNAs are characterized by epigenetic silencing in most cell types, as shown by their enrichment with the histone modification H3K27me3. Our data suggest the presence of an mRNA destabilizing mechanism targeted to these transiently expressed transcription factors to allow their levels to be regulated rapidly with high precision. Our study also demonstrates a general method for measuring mRNA transcription and decay rates in intact organs or tissues, offering insights into the role of mRNA stability in the regulation of complex developmental programs.
Collapse
Affiliation(s)
- Mary Kay Thompson
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Arianna Ceccarelli
- Mathematical Institute, University of Oxford, Oxford OX1 3LB, United Kingdom
| | - David Ish-Horowicz
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Ilan Davis
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| |
Collapse
|
3
|
Salinero AC, Emerson S, Cormier TC, Yin J, Morse RH, Curcio MJ. Reliance of Host-Encoded Regulators of Retromobility on Ty1 Promoter Activity or Architecture. Front Mol Biosci 2022; 9:896215. [PMID: 35847981 PMCID: PMC9283973 DOI: 10.3389/fmolb.2022.896215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
The Ty1 retrotransposon family is maintained in a functional but dormant state by its host, Saccharomyces cerevisiae. Several hundred RHF and RTT genes encoding co-factors and restrictors of Ty1 retromobility, respectively, have been identified. Well-characterized examples include MED3 and MED15, encoding subunits of the Mediator transcriptional co-activator complex; control of retromobility by Med3 and Med15 requires the Ty1 promoter in the U3 region of the long terminal repeat. To characterize the U3-dependence of other Ty1 regulators, we screened a library of 188 known rhf and rtt mutants for altered retromobility of Ty1his3AI expressed from the strong, TATA-less TEF1 promoter or the weak, TATA-containing U3 promoter. Two classes of genes, each including both RHFs and RTTs, were identified. The first class comprising 82 genes that regulated Ty1his3AI retromobility independently of U3 is enriched for RHF genes that restrict the G1 phase of the cell cycle and those involved in transcriptional elongation and mRNA catabolism. The second class of 51 genes regulated retromobility of Ty1his3AI driven only from the U3 promoter. Nineteen U3-dependent regulators (U3DRs) also controlled retromobility of Ty1his3AI driven by the weak, TATA-less PSP2 promoter, suggesting reliance on the low activity of U3. Thirty-one U3DRs failed to modulate PPSP2-Ty1his3AI retromobility, suggesting dependence on the architecture of U3. To further investigate the U3-dependency of Ty1 regulators, we developed a novel fluorescence-based assay to monitor expression of p22-Gag, a restriction factor expressed from the internal Ty1i promoter. Many U3DRs had minimal effects on levels of Ty1 RNA, Ty1i RNA or p22-Gag. These findings uncover a role for the Ty1 promoter in integrating signals from diverse host factors to modulate Ty1 RNA biogenesis or fate.
Collapse
Affiliation(s)
- Alicia C. Salinero
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, United States
| | - Simey Emerson
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Tayla C. Cormier
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - John Yin
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Randall H. Morse
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, United States
| | - M. Joan Curcio
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, United States
- *Correspondence: M. Joan Curcio,
| |
Collapse
|
4
|
Wang C, Barr K, Neutel D, Roy K, Liu Y, Chanfreau GF. Stress-induced inhibition of mRNA export triggers RNase III-mediated decay of the BDF2 mRNA. RNA (NEW YORK, N.Y.) 2021; 27:1545-1556. [PMID: 34497070 PMCID: PMC8594472 DOI: 10.1261/rna.078880.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
The expression of bromodomain-containing proteins that regulate chromatin structure and accessibility must be tightly controlled to ensure the appropriate regulation of gene expression. In the yeast S. cerevisiae, Bromodomain Factor 2 (BDF2) expression is extensively regulated post-transcriptionally during stress by RNase III-mediated decay (RMD), which is triggered by cleavage of the BDF2 mRNA in the nucleus by the RNase III homolog Rnt1p. Previous studies have shown that RMD-mediated down-regulation of BDF2 is hyperactivated in osmotic stress conditions, yet the mechanisms driving the enhanced nuclear cleavage of BDF2 RNA under these conditions remain unknown. Here, we show that RMD hyperactivation can be detected in multiple stress conditions that inhibit mRNA export, and that Rnt1p remains primarily localized in the nucleus during salt stress. We show that globally inhibiting mRNA nuclear export by anchoring away mRNA biogenesis or export factors out of the nucleus can recapitulate RMD hyperactivation in the absence of stress. RMD hyperactivation requires Rnt1p nuclear localization but does not depend on the BDF2 gene endogenous promoter, and its efficiency is affected by the structure of the stem-loop cleaved by Rnt1p. Because multiple stress conditions have been shown to mediate global inhibition of mRNA export, our results suggest that the hyperactivation of RMD is primarily the result of the increased nuclear retention of the BDF2 mRNA during stress.
Collapse
Affiliation(s)
- Charles Wang
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095, USA
| | - Keaton Barr
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095, USA
| | - Dean Neutel
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095, USA
| | - Kevin Roy
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095, USA
- Molecular Biology Institute, UCLA, Los Angeles, California 90095, USA
| | - Yanru Liu
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095, USA
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095, USA
- Molecular Biology Institute, UCLA, Los Angeles, California 90095, USA
| |
Collapse
|
5
|
Yague-Sanz C, Duval M, Larochelle M, Bachand F. Co-transcriptional RNA cleavage by Drosha homolog Pac1 triggers transcription termination in fission yeast. Nucleic Acids Res 2021; 49:8610-8624. [PMID: 34352089 PMCID: PMC8421224 DOI: 10.1093/nar/gkab654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/09/2021] [Accepted: 07/22/2021] [Indexed: 11/13/2022] Open
Abstract
Transcription termination of protein-coding genes in eukaryotic cells usually relies on a tight coordination between the cleavage and polyadenylation of the pre-mRNA, and 5′-3′ degradation of the downstream nascent transcript. Here we investigated the contribution of the essential fission yeast endonuclease Pac1, a homolog of human Drosha that cleaves hairpin RNA structures, in triggering polyadenylation-independent transcription termination. Using ChIP-sequencing in Pac1-deficient cells, we found that Pac1 triggers transcription termination at snRNA and snoRNA genes as well as at specific protein-coding genes. Notably, we found that Pac1-dependent premature termination occurred at two genes encoding conserved transmembrane transporters whose expression were strongly repressed by Pac1. Analysis by genome editing indicated that a stem-loop structure in the nascent transcript directs Pac1-mediated cleavage and that the regions upstream and downstream of the Pac1 cleavage site in the targeted mRNAs were stabilized by mutation of nuclear 3′-5′ and 5′-3′ exonucleases, respectively. Our findings unveil a premature transcription termination pathway that uncouples co-transcriptional RNA cleavage from polyadenylation, triggering rapid nuclear RNA degradation.
Collapse
Affiliation(s)
- Carlo Yague-Sanz
- RNA Group, Department of Biochemistry & Functional Genomics, Université de Sherbrooke, Sherbrooke J1E 4K8, Québec, Canada
| | - Maxime Duval
- RNA Group, Department of Biochemistry & Functional Genomics, Université de Sherbrooke, Sherbrooke J1E 4K8, Québec, Canada
| | - Marc Larochelle
- RNA Group, Department of Biochemistry & Functional Genomics, Université de Sherbrooke, Sherbrooke J1E 4K8, Québec, Canada
| | - François Bachand
- RNA Group, Department of Biochemistry & Functional Genomics, Université de Sherbrooke, Sherbrooke J1E 4K8, Québec, Canada
| |
Collapse
|
6
|
Claude KL, Bureik D, Chatzitheodoridou D, Adarska P, Singh A, Schmoller KM. Transcription coordinates histone amounts and genome content. Nat Commun 2021; 12:4202. [PMID: 34244507 PMCID: PMC8270936 DOI: 10.1038/s41467-021-24451-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 06/18/2021] [Indexed: 02/06/2023] Open
Abstract
Biochemical reactions typically depend on the concentrations of the molecules involved, and cell survival therefore critically depends on the concentration of proteins. To maintain constant protein concentrations during cell growth, global mRNA and protein synthesis rates are tightly linked to cell volume. While such regulation is appropriate for most proteins, certain cellular structures do not scale with cell volume. The most striking example of this is the genomic DNA, which doubles during the cell cycle and increases with ploidy, but is independent of cell volume. Here, we show that the amount of histone proteins is coupled to the DNA content, even though mRNA and protein synthesis globally increase with cell volume. As a consequence, and in contrast to the global trend, histone concentrations decrease with cell volume but increase with ploidy. We find that this distinct coordination of histone homeostasis and genome content is already achieved at the transcript level, and is an intrinsic property of histone promoters that does not require direct feedback mechanisms. Mathematical modeling and histone promoter truncations reveal a simple and generalizable mechanism to control the cell volume- and ploidy-dependence of a given gene through the balance of the initiation and elongation rates.
Collapse
Affiliation(s)
- Kora-Lee Claude
- Institute of Functional Epigenetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Daniela Bureik
- Institute of Functional Epigenetics, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Petia Adarska
- Institute of Functional Epigenetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Abhyudai Singh
- Department of Electrical & Computer Engineering, University of Delaware, Newark, DE, USA
| | - Kurt M Schmoller
- Institute of Functional Epigenetics, Helmholtz Zentrum München, Neuherberg, Germany.
- German Center for Diabetes Research (DZD), Neuherberg, Germany.
| |
Collapse
|
7
|
Wei Z, Zhang Y, Weng W, Chen J, Cai H. Survey and comparative assessments of computational multi-omics integrative methods with multiple regulatory networks identifying distinct tumor compositions across pan-cancer data sets. Brief Bioinform 2020; 22:5856342. [PMID: 32533167 DOI: 10.1093/bib/bbaa102] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/02/2020] [Accepted: 05/04/2020] [Indexed: 12/20/2022] Open
Abstract
The significance of pan-cancer categories has recently been recognized as widespread in cancer research. Pan-cancer categorizes a cancer based on its molecular pathology rather than an organ. The molecular similarities among multi-omics data found in different cancer types can play several roles in both biological processes and therapeutic developments. Therefore, an integrated analysis for various genomic data is frequently used to reveal novel genetic and molecular mechanisms. However, a variety of algorithms for multi-omics clustering have been proposed in different fields. The comparison of different computational clustering methods in pan-cancer analysis performance remains unclear. To increase the utilization of current integrative methods in pan-cancer analysis, we first provide an overview of five popular computational integrative tools: similarity network fusion, integrative clustering of multiple genomic data types (iCluster), cancer integration via multi-kernel learning (CIMLR), perturbation clustering for data integration and disease subtyping (PINS) and low-rank clustering (LRACluster). Then, a priori interactions in multi-omics data were incorporated to detect prominent molecular patterns in pan-cancer data sets. Finally, we present comparative assessments of these methods, with discussion over key issues in applying these algorithms. We found that all five methods can identify distinct tumor compositions. The pan-cancer samples can be reclassified into several groups by different proportions. Interestingly, each method can classify the tumors into categories that are different from original cancer types or subtypes, especially for ovarian serous cystadenocarcinoma (OV) and breast invasive carcinoma (BRCA) tumors. In addition, all clusters of the five computational methods show notable prognostic values. Furthermore, both the 9 recurrent differential genes and the 15 common pathway characteristics were identified across all the methods. The results and discussion can help the community select appropriate integrative tools according to different research tasks or aims in pan-cancer analysis.
Collapse
Affiliation(s)
- Zhuohui Wei
- Computer Science and Engineering, South China University of Technology
| | - Yue Zhang
- School of Computer Science, Guangdong Polytechnic Normal University
| | - Wanlin Weng
- Computer Science and Engineering, South China University of Technology
| | - Jiazhou Chen
- Computer Science and Engineering, South China University of Technology
| | - Hongmin Cai
- Computer Science and Engineering, South China University of Technology
| |
Collapse
|
8
|
Gorin G, Wang M, Golding I, Xu H. Stochastic simulation and statistical inference platform for visualization and estimation of transcriptional kinetics. PLoS One 2020; 15:e0230736. [PMID: 32214380 PMCID: PMC7098607 DOI: 10.1371/journal.pone.0230736] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/06/2020] [Indexed: 12/20/2022] Open
Abstract
Recent advances in single-molecule fluorescent imaging have enabled quantitative measurements of transcription at a single gene copy, yet an accurate understanding of transcriptional kinetics is still lacking due to the difficulty of solving detailed biophysical models. Here we introduce a stochastic simulation and statistical inference platform for modeling detailed transcriptional kinetics in prokaryotic systems, which has not been solved analytically. The model includes stochastic two-state gene activation, mRNA synthesis initiation and stepwise elongation, release to the cytoplasm, and stepwise co-transcriptional degradation. Using the Gillespie algorithm, the platform simulates nascent and mature mRNA kinetics of a single gene copy and predicts fluorescent signals measurable by time-lapse single-cell mRNA imaging, for different experimental conditions. To approach the inverse problem of estimating the kinetic parameters of the model from experimental data, we develop a heuristic optimization method based on the genetic algorithm and the empirical distribution of mRNA generated by simulation. As a demonstration, we show that the optimization algorithm can successfully recover the transcriptional kinetics of simulated and experimental gene expression data. The platform is available as a MATLAB software package at https://data.caltech.edu/records/1287.
Collapse
Affiliation(s)
- Gennady Gorin
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Mengyu Wang
- Department of Physics, Grainger College of Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Ido Golding
- Department of Physics, Grainger College of Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Heng Xu
- School of Physics and Astronomy, Shanghai Jiao Tong University, Minhang District, Shanghai, China
- Institute of Natural Sciences, Shanghai Jiao Tong University, Minhang District, Shanghai, China
- * E-mail:
| |
Collapse
|