1
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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.
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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.
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2
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Maturation and shuttling of the yeast telomerase RNP: assembling something new using recycled parts. Curr Genet 2021; 68:3-14. [PMID: 34476547 PMCID: PMC8801399 DOI: 10.1007/s00294-021-01210-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 11/10/2022]
Abstract
As the limiting component of the budding yeast telomerase, the Tlc1 RNA must undergo multiple consecutive modifications and rigorous quality checks throughout its lifecycle. These steps will ensure that only correctly processed and matured molecules are assembled into telomerase complexes that subsequently act at telomeres. The complex pathway of Tlc1 RNA maturation, involving 5'- and 3'-end processing, stabilisation and assembly with the protein subunits, requires at least one nucleo-cytoplasmic passage. Furthermore, it appears that the pathway is tightly coordinated with the association of various and changing proteins, including the export factor Xpo1, the Mex67/Mtr2 complex, the Kap122 importin, the Sm7 ring and possibly the CBC and TREX-1 complexes. Although many of these maturation processes also affect other RNA species, the Tlc1 RNA exploits them in a new combination and, therefore, ultimately follows its own and unique pathway. In this review, we highlight recent new insights in maturation and subcellular shuttling of the budding yeast telomerase RNA and discuss how these events may be fine-tuned by the biochemical characteristics of the varying processing and transport factors as well as the final telomerase components. Finally, we indicate outstanding questions that we feel are important to be addressed for a complete understanding of the telomerase RNA lifecycle and that could have implications for the human telomerase as well.
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3
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Zappulla DC. Yeast Telomerase RNA Flexibly Scaffolds Protein Subunits: Results and Repercussions. Molecules 2020; 25:E2750. [PMID: 32545864 PMCID: PMC7356895 DOI: 10.3390/molecules25122750] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/09/2020] [Accepted: 06/11/2020] [Indexed: 12/25/2022] Open
Abstract
It is said that "hindsight is 20-20", so, given the current year, it is an opportune time to review and learn from experiences studying long noncoding RNAs. Investigation of the Saccharomyces cerevisiae telomerase RNA, TLC1, has unveiled striking flexibility in terms of both structural and functional features. Results support the "flexible scaffold" hypothesis for this 1157-nt telomerase RNA. This model describes TLC1 acting as a tether for holoenzyme protein subunits, and it also may apply to a plethora of RNAs beyond telomerase, such as types of lncRNAs. In this short perspective review, I summarize findings from studying the large yeast telomerase ribonucleoprotein (RNP) complex in the hope that this hindsight will sharpen foresight as so many of us seek to mechanistically understand noncoding RNA molecules from vast transcriptomes.
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Affiliation(s)
- David C Zappulla
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
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4
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Garcia PD, Leach RW, Wadsworth GM, Choudhary K, Li H, Aviran S, Kim HD, Zakian VA. Stability and nuclear localization of yeast telomerase depend on protein components of RNase P/MRP. Nat Commun 2020; 11:2173. [PMID: 32358529 PMCID: PMC7195438 DOI: 10.1038/s41467-020-15875-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 03/27/2020] [Indexed: 01/17/2023] Open
Abstract
RNase P and MRP are highly conserved, multi-protein/RNA complexes with essential roles in processing ribosomal and tRNAs. Three proteins found in both complexes, Pop1, Pop6, and Pop7 are also telomerase-associated. Here, we determine how temperature sensitive POP1 and POP6 alleles affect yeast telomerase. At permissive temperatures, mutant Pop1/6 have little or no effect on cell growth, global protein levels, the abundance of Est1 and Est2 (telomerase proteins), and the processing of TLC1 (telomerase RNA). However, in pop mutants, TLC1 is more abundant, telomeres are short, and TLC1 accumulates in the cytoplasm. Although Est1/2 binding to TLC1 occurs at normal levels, Est1 (and hence Est3) binding is highly unstable. We propose that Pop-mediated stabilization of Est1 binding to TLC1 is a pre-requisite for formation and nuclear localization of the telomerase holoenzyme. Furthermore, Pop proteins affect TLC1 and the RNA subunits of RNase P/MRP in very different ways.
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Affiliation(s)
- P Daniela Garcia
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Robert W Leach
- Bioinformatics Group, Genomics Core Facility, Carl Icahn Laboratory, Princeton University, Princeton, New Jersey, 08544, USA
| | - Gable M Wadsworth
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA
| | - Krishna Choudhary
- Department of Biomedical Engineering and Genome Center, University of California, Davis, California, 95616, USA
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, 94158, USA
| | - Hua Li
- Department of Biomedical Engineering and Genome Center, University of California, Davis, California, 95616, USA
| | - Sharon Aviran
- Department of Biomedical Engineering and Genome Center, University of California, Davis, California, 95616, USA
| | - Harold D Kim
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA
| | - Virginia A Zakian
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
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5
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Červenák F, Juríková K, Devillers H, Kaffe B, Khatib A, Bonnell E, Sopkovičová M, Wellinger RJ, Nosek J, Tzfati Y, Neuvéglise C, Tomáška Ľ. Identification of telomerase RNAs in species of the Yarrowia clade provides insights into the co-evolution of telomerase, telomeric repeats and telomere-binding proteins. Sci Rep 2019; 9:13365. [PMID: 31527614 PMCID: PMC6746865 DOI: 10.1038/s41598-019-49628-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 07/29/2019] [Indexed: 12/17/2022] Open
Abstract
Telomeric repeats in fungi of the subphylum Saccharomycotina exhibit great inter- and intra-species variability in length and sequence. Such variations challenged telomeric DNA-binding proteins that co-evolved to maintain their functions at telomeres. Here, we compare the extent of co-variations in telomeric repeats, encoded in the telomerase RNAs (TERs), and the repeat-binding proteins from 13 species belonging to the Yarrowia clade. We identified putative TER loci, analyzed their sequence and secondary structure conservation, and predicted functional elements. Moreover, in vivo complementation assays with mutant TERs showed the functional importance of four novel TER substructures. The TER-derived telomeric repeat unit of all species, except for one, is 10 bp long and can be represented as 5′-TTNNNNAGGG-3′, with repeat sequence variations occuring primarily outside the vertebrate telomeric motif 5′-TTAGGG-3′. All species possess a homologue of the Yarrowia lipolytica Tay1 protein, YlTay1p. In vitro, YlTay1p displays comparable DNA-binding affinity to all repeat variants, suggesting a conserved role among these species. Taken together, these results add significant insights into the co-evolution of TERs, telomeric repeats and telomere-binding proteins in yeasts.
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Affiliation(s)
- Filip Červenák
- Departments of Genetics and Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, Mlynská dolina, 84215, Bratislava, Slovakia
| | - Katarína Juríková
- Departments of Genetics and Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, Mlynská dolina, 84215, Bratislava, Slovakia
| | - Hugo Devillers
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Binyamin Kaffe
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Safra Campus, Jerusalem, 91904, Israel
| | - Areej Khatib
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Safra Campus, Jerusalem, 91904, Israel
| | - Erin Bonnell
- Department of Microbiology and Infectiology, RNA Group, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, J1E 4K8, Canada
| | - Martina Sopkovičová
- Departments of Genetics and Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, Mlynská dolina, 84215, Bratislava, Slovakia
| | - Raymund J Wellinger
- Department of Microbiology and Infectiology, RNA Group, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, J1E 4K8, Canada
| | - Jozef Nosek
- Departments of Genetics and Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, Mlynská dolina, 84215, Bratislava, Slovakia
| | - Yehuda Tzfati
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Safra Campus, Jerusalem, 91904, Israel.
| | - Cécile Neuvéglise
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.
| | - Ľubomír Tomáška
- Departments of Genetics and Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Ilkovičova 6, Mlynská dolina, 84215, Bratislava, Slovakia.
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6
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Laterreur N, Lemieux B, Neumann H, Berger-Dancause JC, Lafontaine D, Wellinger RJ. The yeast telomerase module for telomere recruitment requires a specific RNA architecture. RNA (NEW YORK, N.Y.) 2018; 24:1067-1079. [PMID: 29777050 PMCID: PMC6049500 DOI: 10.1261/rna.066696.118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 05/17/2018] [Indexed: 06/08/2023]
Abstract
Telomerases are ribonucleoprotein (RNP) reverse transcriptases. While telomerases maintain genome stability, their composition varies significantly between species. Yeast telomerase RNPs contain an RNA that is comparatively large, and its overall folding shows long helical segments with distal functional parts. Here we investigated the essential stem IVc module of the budding yeast telomerase RNA, called Tlc1. The distal part of stem IVc includes a conserved sequence element CS2a and structurally conserved features for binding Pop1/Pop6/Pop7 proteins, which together function analogously to the P3 domains of the RNase P/MRP RNPs. A more proximal bulged stem with the CS2 element is thought to associate with Est1, a telomerase protein required for telomerase recruitment to telomeres. Previous work found that changes in CS2a cause a loss of all stem IVc proteins, not just the Pop proteins. Here we show that the association of Est1 with stem IVc indeed requires both the proximal bulged stem and the P3 domain with the associated Pop proteins. Separating the P3 domain from the Est1 binding site by inserting only 2 base pairs into the helical stem between the two sites causes a complete loss of Est1 from the RNP and hence a telomerase-negative phenotype in vivo. Still, the distal P3 domain with the associated Pop proteins remains intact. Moreover, the P3 domain ensures Est2 stability on the RNP independently of Est1 association. Therefore, the Tlc1 stem IVc recruitment module of the RNA requires a very tight architectural organization for telomerase function in vivo.
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Affiliation(s)
- Nancy Laterreur
- Department of Microbiology and Infectiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, PRAC, Sherbrooke, Québec J1E 4K8, Canada
| | - Bruno Lemieux
- Department of Microbiology and Infectiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, PRAC, Sherbrooke, Québec J1E 4K8, Canada
| | - Hannah Neumann
- Department of Microbiology and Infectiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, PRAC, Sherbrooke, Québec J1E 4K8, Canada
| | | | - Daniel Lafontaine
- Department of Biology, Faculty of Sciences, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Raymund J Wellinger
- Department of Microbiology and Infectiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, PRAC, Sherbrooke, Québec J1E 4K8, Canada
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7
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Laterreur N, Wellinger RJ. [A rejuvenation for yeast telomerase]. Med Sci (Paris) 2017; 33:1051-1054. [PMID: 29261492 DOI: 10.1051/medsci/20173312011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Nancy Laterreur
- Département de microbiologie et infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3201 Rue Jean Mignault Sherbrooke, Québec, J1E 4K8, Canada
| | - Raymund J Wellinger
- Département de microbiologie et infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3201 Rue Jean Mignault Sherbrooke, Québec, J1E 4K8, Canada
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8
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Abstract
The addition of telomeric DNA to chromosome ends is an essential cellular activity that compensates for the loss of genomic DNA that is due to the inability of the conventional DNA replication apparatus to duplicate the entire chromosome. The telomerase reverse transcriptase and its associated RNA bind to the very end of the telomere via a sequence in the RNA and specific protein-protein interactions. Telomerase RNA also provides the template for addition of new telomeric repeats by the reverse-transcriptase protein subunit. In addition to the template, there are 3 other conserved regions in telomerase RNA that are essential for normal telomerase activity. Here we briefly review the conserved core regions of telomerase RNA and then focus on a recent study in fission yeast that determined the function of another conserved region in telomerase RNA called the Stem Terminus Element (STE). (1) The STE is distant from the templating core of telomerase in both the linear and RNA secondary structure, but, nonetheless, affects the fidelity of telomere sequence addition and, in turn, the ability of telomere binding proteins to bind and protect chromosome ends. We will discuss possible mechanisms of STE action and the suitability of the STE as an anti-cancer target.
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Affiliation(s)
- Christopher J Webb
- a Department of Molecular Biology , Princeton University , Princeton , NJ , USA
| | - Virginia A Zakian
- a Department of Molecular Biology , Princeton University , Princeton , NJ , USA
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9
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Lemieux B, Laterreur N, Perederina A, Noël JF, Dubois ML, Krasilnikov AS, Wellinger RJ. Active Yeast Telomerase Shares Subunits with Ribonucleoproteins RNase P and RNase MRP. Cell 2016; 165:1171-1181. [PMID: 27156450 DOI: 10.1016/j.cell.2016.04.018] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 02/20/2016] [Accepted: 04/01/2016] [Indexed: 01/01/2023]
Abstract
Telomerase is the ribonucleoprotein enzyme that replenishes telomeric DNA and maintains genome integrity. Minimally, telomerase activity requires a templating RNA and a catalytic protein. Additional proteins are required for activity on telomeres in vivo. Here, we report that the Pop1, Pop6, and Pop7 proteins, known components of RNase P and RNase MRP, bind to yeast telomerase RNA and are essential constituents of the telomerase holoenzyme. Pop1/Pop6/Pop7 binding is specific and involves an RNA domain highly similar to a protein-binding domain in the RNAs of RNase P/MRP. The results also show that Pop1/Pop6/Pop7 function to maintain the essential components Est1 and Est2 on the RNA in vivo. Consistently, addition of Pop1 allows for telomerase activity reconstitution with wild-type telomerase RNA in vitro. Thus, the same chaperoning module has allowed the evolution of functionally and, remarkably, structurally distinct RNPs, telomerase, and RNases P/MRP from unrelated progenitor RNAs.
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Affiliation(s)
- Bruno Lemieux
- Department of Microbiology and Infectious Diseases, Center of Excellence in RNA Biology, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada
| | - Nancy Laterreur
- Department of Microbiology and Infectious Diseases, Center of Excellence in RNA Biology, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada
| | - Anna Perederina
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Jean-François Noël
- Department of Microbiology and Infectious Diseases, Center of Excellence in RNA Biology, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada
| | - Marie-Line Dubois
- Department of Anatomy and Cellular Biology,Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada
| | - Andrey S Krasilnikov
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Raymund J Wellinger
- Department of Microbiology and Infectious Diseases, Center of Excellence in RNA Biology, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada.
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10
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Telomerase RNA stem terminus element affects template boundary element function, telomere sequence, and shelterin binding. Proc Natl Acad Sci U S A 2015; 112:11312-7. [PMID: 26305931 DOI: 10.1073/pnas.1503157112] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The stem terminus element (STE), which was discovered 13 y ago in human telomerase RNA, is required for telomerase activity, yet its mode of action is unknown. We report that the Schizosaccharomyces pombe telomerase RNA, TER1 (telomerase RNA 1), also contains a STE, which is essential for telomere maintenance. Cells expressing a partial loss-of-function TER1 STE allele maintained short stable telomeres by a recombination-independent mechanism. Remarkably, the mutant telomere sequence was different from that of wild-type cells. Generation of the altered sequence is explained by reverse transcription into the template boundary element, demonstrating that the STE helps maintain template boundary element function. The altered telomeres bound less Pot1 (protection of telomeres 1) and Taz1 (telomere-associated in Schizosaccharomyces pombe 1) in vivo. Thus, the S. pombe STE, although distant from the template, ensures proper telomere sequence, which in turn promotes proper assembly of the shelterin complex.
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11
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Lebo KJ, Niederer RO, Zappulla DC. A second essential function of the Est1-binding arm of yeast telomerase RNA. RNA (NEW YORK, N.Y.) 2015; 21:862-876. [PMID: 25737580 PMCID: PMC4408794 DOI: 10.1261/rna.049379.114] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 12/29/2014] [Indexed: 06/04/2023]
Abstract
The enzymatic ribonucleoprotein telomerase maintains telomeres in many eukaryotes, including humans, and plays a central role in aging and cancer. Saccharomyces cerevisiae telomerase RNA, TLC1, is a flexible scaffold that tethers telomerase holoenzyme protein subunits to the complex. Here we test the hypothesis that a lengthy conserved region of the Est1-binding TLC1 arm contributes more than simply Est1-binding function. We separated Est1 binding from potential other functions by tethering TLC1 to Est1 via a heterologous RNA-protein binding module. We find that Est1-tethering rescues in vivo function of telomerase RNA alleles missing nucleotides specifically required for Est1 binding, but not those missing the entire conserved region. Notably, however, telomerase function is restored for this condition by expressing the arm of TLC1 in trans. Mutational analysis shows that the Second Essential Est1-arm Domain (SEED) maps to an internal loop of the arm, which SHAPE chemical mapping and 3D modeling suggest could be regulated by conformational change. Finally, we find that the SEED has an essential, Est1-independent role in telomerase function after telomerase recruitment to the telomere. The SEED may be required for establishing telomere extendibility or promoting telomerase RNP holoenzyme activity.
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Affiliation(s)
- Kevin J Lebo
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
| | - Rachel O Niederer
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
| | - David C Zappulla
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
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12
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Progress in structural studies of telomerase. Curr Opin Struct Biol 2014; 24:115-24. [PMID: 24508601 DOI: 10.1016/j.sbi.2014.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 01/01/2014] [Accepted: 01/08/2014] [Indexed: 02/01/2023]
Abstract
Telomerase is the ribonucleoprotein (RNP) reverse transcriptase responsible for synthesizing the 3' ends of linear chromosomes. It plays critical roles in tumorigenesis, cellular aging, and stem cell renewal. The past two years have seen exciting progress in determining telomerase holoenzyme architecture and the structural basis of telomerase activity. Notably, the first electron microscopy structures of telomerase were reported, of the Tetrahymena thermophila telomerase holoenzyme and a human telomerase dimer. In addition to new structures of TERT and TER domains, the first structures of telomerase protein domains beyond TERT, and their complexes with TER or telomeric single-stranded DNA, were reported. Together these studies provide the first glimpse into the organization of the proteins and RNA in the telomerase RNP.
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13
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Abstract
Telomerase reverse transcriptase (TERT) is the protein component of telomerase and combined with an RNA molecule, telomerase RNA component, forms the telomerase enzyme responsible for telomere elongation. Telomerase is essential for maintaining telomere length from replicative attrition and thus contributes to the preservation of genome integrity. Although diverse mouse models have been developed and studied to prove the physiological roles of telomerase as a telomere- elongating enzyme, recent studies have revealed non-canonical TERT activities beyond telomeres. To gain insights into the physiological impact of extra-telomeric roles, this review revisits the strategies and phenotypes of telomerase mouse models in terms of the extra-telomeric functions of telomerase.
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Affiliation(s)
- Young Hoon Sung
- Department of Biochemistry, College of Life Science and Biotechnology, Laboratory Animal Research Center, Yonsei University, Seoul, Korea
| | - Muhammad Ali
- Department of Biochemistry, College of Life Science and Biotechnology, Laboratory Animal Research Center, Yonsei University, Seoul, Korea
| | - Han-Woong Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Laboratory Animal Research Center, Yonsei University, Seoul, Korea
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