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da Silva VL, de Paiva SC, de Oliveira HC, Fernandes CAH, Salvador GHM, Fontes MRDM, Cano MIN. Biochemical and structural characterization of the RT domain of Leishmania sp. telomerase reverse transcriptase. Biochim Biophys Acta Gen Subj 2023; 1867:130451. [PMID: 37751810 DOI: 10.1016/j.bbagen.2023.130451] [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: 12/13/2022] [Revised: 07/22/2023] [Accepted: 08/25/2023] [Indexed: 09/28/2023]
Abstract
BACKGROUND The Leishmania genus comprises parasites that cause leishmaniasis, a neglected disease spread worldwide. Leishmania sp. telomeres are composed of TTAGGG repeats maintained by telomerase. In most eukaryotes, the enzyme minimal complex contains the TER (telomerase RNA) and the TERT (telomerase reverse transcriptase) components. The TERT holds the enzyme catalytic core and is formed by four structural and functional domains (TEN, Telomerase Essential N-terminal; TRBD, Telomerase RNA Binding Domain; RT, the reverse transcriptase domain and CTE, C-Terminal Extension domain). METHODS AND RESULTS Amino acid sequence alignments, protein structure prediction analysis, and protein: nucleic acid interaction assays were used to show that the Leishmania major RT domain preserves the canonical structural elements found in higher eukaryotes, including the canonical motifs and the aspartic acid residues that stabilize the Mg2+ ion cofactor. Furthermore, amino acid substitutions specific to the Leishmania genus and partial conservation of the residues involved with nucleic acid interactions are shown. The purified recombinant Leishmania RT protein is biochemically active and interacts with the G-rich telomeric strand and the TER template sequence. CONCLUSION Our results highlight that the telomerase catalysis mechanism is conserved in a pathogen of medical importance despite the structural peculiarities present in the parasite's RT domain.
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Affiliation(s)
- Vitor Luiz da Silva
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Stephany Cacete de Paiva
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Hamine Cristina de Oliveira
- Department of Biophysics and Pharmacology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Carlos Alexandre H Fernandes
- UMR 7590, CNRS, Muséum National d'Histoire Naturelle, IRD, Institut de Minéralogie, Physique des Matériaux et de Cosmochimie, IMPMC, Sorbonne Université, Paris, France
| | | | - Marcos Roberto de M Fontes
- Department of Biophysics and Pharmacology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, SP, Brazil; Institute for Advanced Studies of the Sea (IEAMAR), São Paulo State University (UNESP), São Vicente, SP, Brazil
| | - Maria Isabel N Cano
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, SP, Brazil.
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Davis JA, Reyes AV, Nitika, Saha A, Wolfgeher DJ, Xu SL, Truman AW, Li B, Chakrabarti K. Proteomic analysis defines the interactome of telomerase in the protozoan parasite, Trypanosoma brucei. Front Cell Dev Biol 2023; 11:1110423. [PMID: 37009488 PMCID: PMC10061497 DOI: 10.3389/fcell.2023.1110423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 03/03/2023] [Indexed: 03/17/2023] Open
Abstract
Telomerase is a ribonucleoprotein enzyme responsible for maintaining the telomeric end of the chromosome. The telomerase enzyme requires two main components to function: the telomerase reverse transcriptase (TERT) and the telomerase RNA (TR), which provides the template for telomeric DNA synthesis. TR is a long non-coding RNA, which forms the basis of a large structural scaffold upon which many accessory proteins can bind and form the complete telomerase holoenzyme. These accessory protein interactions are required for telomerase activity and regulation inside cells. The interacting partners of TERT have been well studied in yeast, human, and Tetrahymena models, but not in parasitic protozoa, including clinically relevant human parasites. Here, using the protozoan parasite, Trypanosoma brucei (T. brucei) as a model, we have identified the interactome of T. brucei TERT (TbTERT) using a mass spectrometry-based approach. We identified previously known and unknown interacting factors of TbTERT, highlighting unique features of T. brucei telomerase biology. These unique interactions with TbTERT, suggest mechanistic differences in telomere maintenance between T. brucei and other eukaryotes.
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Affiliation(s)
- Justin A. Davis
- Department of Biological Sciences, University of North Carolina, Charlotte, NC, United States
| | - Andres V. Reyes
- Department of Plant Biology and Carnegie Mass Spectrometry Facility, Carnegie Institution for Science, Stanford, CA, United States
| | - Nitika
- Department of Biological Sciences, University of North Carolina, Charlotte, NC, United States
| | - Arpita Saha
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Arts and Sciences, Cleveland State University, Cleveland, OH, United States
| | - Donald J. Wolfgeher
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, United States
| | - Shou-Ling Xu
- Department of Plant Biology and Carnegie Mass Spectrometry Facility, Carnegie Institution for Science, Stanford, CA, United States
| | - Andrew W. Truman
- Department of Biological Sciences, University of North Carolina, Charlotte, NC, United States
| | - Bibo Li
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Arts and Sciences, Cleveland State University, Cleveland, OH, United States
| | - Kausik Chakrabarti
- Department of Biological Sciences, University of North Carolina, Charlotte, NC, United States
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Davis JA, Chakrabarti K. Telomerase ribonucleoprotein and genome integrity-An emerging connection in protozoan parasites. WILEY INTERDISCIPLINARY REVIEWS. RNA 2021; 13:e1710. [PMID: 34973045 DOI: 10.1002/wrna.1710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 12/08/2021] [Accepted: 12/10/2021] [Indexed: 12/20/2022]
Abstract
Telomerase has an established role in telomere maintenance in eukaryotes. However, recent studies have begun to implicate telomerase in cellular roles beyond telomere maintenance. Specifically, evidence is emerging of cross-talks between telomerase mediated telomere homeostasis and DNA repair pathways. Telomere shortening due to the end replication problem is a constant threat to genome integrity in eukaryotic cells. This poses a particular problem in unicellular parasitic protists because their major virulence genes are located at the subtelomeric loci. Although telomerase is the major regulator of telomere lengthening in eukaryotes, it is less studied in the ancient eukaryotes, including clinically important human pathogens. Recent research is highlighting interplay between telomerase and the DNA damage response in human parasites. The importance of this interplay in pathogen virulence is only beginning to be illuminated, including the potential to highlight novel developmental regulation of telomerase in parasites who transition between multiple developmental stages throughout their life cycle. In this review, we will discuss the telomerase ribonucleoprotein enzyme and DNA repair pathways with emerging views in human parasites to give a broader perspective of the possible connection of telomere, telomerase, and DNA repair pathways across eukaryotic lineages and highlight their potential role in pathogen virulence. This article is categorized under: RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
| | - Kausik Chakrabarti
- University of North Carolina at Charlotte, Charlotte, North Carolina, USA
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de Oliveira BCD, Shiburah ME, Paiva SC, Vieira MR, Morea EGO, da Silva MS, Alves CDS, Segatto M, Gutierrez-Rodrigues F, Borges JC, Calado RT, Cano MIN. Possible Involvement of Hsp90 in the Regulation of Telomere Length and Telomerase Activity During the Leishmania amazonensis Developmental Cycle and Population Proliferation. Front Cell Dev Biol 2021; 9:713415. [PMID: 34778247 PMCID: PMC8581162 DOI: 10.3389/fcell.2021.713415] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 09/29/2021] [Indexed: 12/29/2022] Open
Abstract
The Leishmania developmental cycle comprises three main life forms in two hosts, indicating that the parasite is continually challenged due to drastic environmental changes. The disruption of this cycle is critical for discovering new therapies to eradicate leishmaniasis, a neglected disease that affects millions worldwide. Telomeres, the physical ends of chromosomes, maintain genome stability and cell proliferation and are potential antiparasitic drug targets. Therefore, understanding how telomere length is regulated during parasite development is vital. Here, we show that telomeres form clusters spread in the nucleoplasm of the three parasite life forms. We also observed that amastigotes telomeres are shorter than metacyclic and procyclic promastigotes and that in parasites with continuous in vitro passages, telomere length increases over time. These observed differences in telomere length among parasite’s life stages were not due to lack/inhibition of telomerase since enzyme activity was detected in all parasite life stages, although the catalysis was temperature-dependent. These data led us to test if, similar to other eukaryotes, parasite telomere length maintenance could be regulated by Hsp83, the ortholog of Hsp90 in trypanosomatids, and Leishmania (LHsp90). Parasites were then treated with the Hsp90 inhibitor 17AAG. The results showed that 17AAG disturbed parasite growth, induced accumulation into G2/M phases, and telomere shortening in a time-dependent manner. It has also inhibited procyclic promastigote’s telomerase activity. Besides, LHsp90 interacts with the telomerase TERT component as shown by immunoprecipitation, strongly suggesting a new role for LHsp90 as a parasite telomerase component involved in controlling telomere length maintenance and parasite life span.
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Affiliation(s)
- Beatriz C D de Oliveira
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), São Paulo, Brazil
| | - Mark E Shiburah
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), São Paulo, Brazil
| | - Stepany C Paiva
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), São Paulo, Brazil
| | - Marina R Vieira
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), São Paulo, Brazil
| | - Edna Gicela O Morea
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), São Paulo, Brazil
| | - Marcelo Santos da Silva
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), São Paulo, Brazil
| | - Cristiane de Santis Alves
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), São Paulo, Brazil
| | | | | | - Júlio C Borges
- São Carlos Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Rodrigo T Calado
- Hemocentro da Faculdade de Medicina de Ribeirão Preto, Universidade of São Paulo, São Paulo, Brazil
| | - Maria Isabel N Cano
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), São Paulo, Brazil
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Assis LHC, Andrade-Silva D, Shiburah ME, de Oliveira BCD, Paiva SC, Abuchery BE, Ferri YG, Fontes VS, de Oliveira LS, da Silva MS, Cano MIN. Cell Cycle, Telomeres, and Telomerase in Leishmania spp.: What Do We Know So Far? Cells 2021; 10:cells10113195. [PMID: 34831418 PMCID: PMC8621916 DOI: 10.3390/cells10113195] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/12/2021] [Accepted: 11/14/2021] [Indexed: 12/18/2022] Open
Abstract
Leishmaniases belong to the inglorious group of neglected tropical diseases, presenting different degrees of manifestations severity. It is caused by the transmission of more than 20 species of parasites of the Leishmania genus. Nevertheless, the disease remains on the priority list for developing new treatments, since it affects millions in a vast geographical area, especially low-income people. Molecular biology studies are pioneers in parasitic research with the aim of discovering potential targets for drug development. Among them are the telomeres, DNA–protein structures that play an important role in the long term in cell cycle/survival. Telomeres are the physical ends of eukaryotic chromosomes. Due to their multiple interactions with different proteins that confer a likewise complex dynamic, they have emerged as objects of interest in many medical studies, including studies on leishmaniases. This review aims to gather information and elucidate what we know about the phenomena behind Leishmania spp. telomere maintenance and how it impacts the parasite’s cell cycle.
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Affiliation(s)
- Luiz H. C. Assis
- Telomeres Laboratory, Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (L.H.C.A.); (D.A.-S.); (M.E.S.); (B.C.D.d.O.); (S.C.P.); (V.S.F.); (L.S.d.O.)
| | - Débora Andrade-Silva
- Telomeres Laboratory, Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (L.H.C.A.); (D.A.-S.); (M.E.S.); (B.C.D.d.O.); (S.C.P.); (V.S.F.); (L.S.d.O.)
| | - Mark E. Shiburah
- Telomeres Laboratory, Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (L.H.C.A.); (D.A.-S.); (M.E.S.); (B.C.D.d.O.); (S.C.P.); (V.S.F.); (L.S.d.O.)
| | - Beatriz C. D. de Oliveira
- Telomeres Laboratory, Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (L.H.C.A.); (D.A.-S.); (M.E.S.); (B.C.D.d.O.); (S.C.P.); (V.S.F.); (L.S.d.O.)
| | - Stephany C. Paiva
- Telomeres Laboratory, Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (L.H.C.A.); (D.A.-S.); (M.E.S.); (B.C.D.d.O.); (S.C.P.); (V.S.F.); (L.S.d.O.)
| | - Bryan E. Abuchery
- DNA Replication and Repair Laboratory (DRRL), Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (B.E.A.); (Y.G.F.)
| | - Yete G. Ferri
- DNA Replication and Repair Laboratory (DRRL), Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (B.E.A.); (Y.G.F.)
| | - Veronica S. Fontes
- Telomeres Laboratory, Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (L.H.C.A.); (D.A.-S.); (M.E.S.); (B.C.D.d.O.); (S.C.P.); (V.S.F.); (L.S.d.O.)
| | - Leilane S. de Oliveira
- Telomeres Laboratory, Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (L.H.C.A.); (D.A.-S.); (M.E.S.); (B.C.D.d.O.); (S.C.P.); (V.S.F.); (L.S.d.O.)
| | - Marcelo S. da Silva
- DNA Replication and Repair Laboratory (DRRL), Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (B.E.A.); (Y.G.F.)
- Correspondence: (M.S.d.S.); (M.I.N.C.)
| | - Maria Isabel N. Cano
- Telomeres Laboratory, Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (L.H.C.A.); (D.A.-S.); (M.E.S.); (B.C.D.d.O.); (S.C.P.); (V.S.F.); (L.S.d.O.)
- Correspondence: (M.S.d.S.); (M.I.N.C.)
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Current Perspectives of Telomerase Structure and Function in Eukaryotes with Emerging Views on Telomerase in Human Parasites. Int J Mol Sci 2018; 19:ijms19020333. [PMID: 29364142 PMCID: PMC5855555 DOI: 10.3390/ijms19020333] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 01/10/2018] [Accepted: 01/17/2018] [Indexed: 12/11/2022] Open
Abstract
Replicative capacity of a cell is strongly correlated with telomere length regulation. Aberrant lengthening or reduction in the length of telomeres can lead to health anomalies, such as cancer or premature aging. Telomerase is a master regulator for maintaining replicative potential in most eukaryotic cells. It does so by controlling telomere length at chromosome ends. Akin to cancer cells, most single-cell eukaryotic pathogens are highly proliferative and require persistent telomerase activity to maintain constant length of telomere and propagation within their host. Although telomerase is key to unlimited cellular proliferation in both cases, not much was known about the role of telomerase in human parasites (malaria, Trypanosoma, etc.) until recently. Since telomerase regulation is mediated via its own structural components, interactions with catalytic reverse transcriptase and several factors that can recruit and assemble telomerase to telomeres in a cell cycle-dependent manner, we compare and discuss here recent findings in telomerase biology in cancer, aging and parasitic diseases to give a broader perspective of telomerase function in human diseases.
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Telomerase activity is required for the telomere G-overhang structure in Trypanosoma brucei. Sci Rep 2017; 7:15983. [PMID: 29167542 PMCID: PMC5700094 DOI: 10.1038/s41598-017-16182-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 11/08/2017] [Indexed: 01/24/2023] Open
Abstract
Trypanosoma brucei causes fatal human African trypanosomiasis and evades the host immune response by regularly switching its major surface antigen, VSG, which is expressed exclusively from subtelomeric loci. Telomere length and telomere proteins play important roles in regulating VSG silencing and switching. T. brucei telomerase plays a key role in maintaining telomere length, and T. brucei telomeres terminate in a single-stranded 3′ G-rich overhang. Understanding the detailed structure of the telomere G-overhang and its maintenance will contribute greatly to better understanding telomere maintenance mechanisms. Using an optimized adaptor ligation assay, we found that most T. brucei telomere G-overhangs end in 5′ TTAGGG 3′, while a small portion of G-overhangs end in 5′ TAGGGT 3′. Additionally, the protein and the RNA components of the telomerase (TbTERT and TbTR) and TbKu are required for telomere G-overhangs that end in 5′ TTAGGG 3′ but do not significantly affect the 5′ TAGGGT 3′-ending overhangs, indicating that telomerase-mediated telomere synthesis is important for the telomere G-overhang structure. Furthermore, using telomere oligo ligation-mediated PCR, we showed for the first time that the T. brucei telomere 5′ end sequence – an important feature of the telomere terminal structure – is not random but preferentially 5′ CCTAAC 3′.
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Morea EGO, Viviescas MA, Fernandes CAH, Matioli FF, Lira CBB, Fernandez MF, Moraes BS, da Silva MS, Storti CB, Fontes MRM, Cano MIN. A calmodulin-like protein (LCALA) is a new Leishmania amazonensis candidate for telomere end-binding protein. Biochim Biophys Acta Gen Subj 2017; 1861:2583-2597. [PMID: 28844976 DOI: 10.1016/j.bbagen.2017.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 08/06/2017] [Accepted: 08/14/2017] [Indexed: 11/26/2022]
Abstract
BACKGROUND Leishmania spp. telomeres are composed of 5'-TTAGGG-3' repeats associated with proteins. We have previously identified LaRbp38 and LaRPA-1 as proteins that bind the G-rich telomeric strand. At that time, we had also partially characterized a protein: DNA complex, named LaGT1, but we could not identify its protein component. METHODS AND RESULTS Using protein-DNA interaction and competition assays, we confirmed that LaGT1 is highly specific to the G-rich telomeric single-stranded DNA. Three protein bands, with LaGT1 activity, were isolated from affinity-purified protein extracts in-gel digested, and sequenced de novo using mass spectrometry analysis. In silico analysis of the digested peptide identified them as a putative calmodulin with sequences identical to the T. cruzi calmodulin. In the Leishmania genome, the calmodulin ortholog is present in three identical copies. We cloned and sequenced one of the gene copies, named it LCalA, and obtained the recombinant protein. Multiple sequence alignment and molecular modeling showed that LCalA shares homology to most eukaryotes calmodulin. In addition, we demonstrated that LCalA is nuclear, partially co-localizes with telomeres and binds in vivo the G-rich telomeric strand. Recombinant LCalA can bind specifically and with relative affinity to the G-rich telomeric single-strand and to a 3'G-overhang, and DNA binding is calcium dependent. CONCLUSIONS We have described a novel candidate component of Leishmania telomeres, LCalA, a nuclear calmodulin that binds the G-rich telomeric strand with high specificity and relative affinity, in a calcium-dependent manner. GENERAL SIGNIFICANCE LCalA is the first reported calmodulin that binds in vivo telomeric DNA.
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Affiliation(s)
- Edna G O Morea
- Genetics Dept., Biosciences Institute, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | | | - Carlos A H Fernandes
- Biophysics and Physics Dept., Biosciences Institute, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Fabio F Matioli
- Biophysics and Physics Dept., Biosciences Institute, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Cristina B B Lira
- Genetics Dept., Biosciences Institute, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Maribel F Fernandez
- Instituto Tocantinense Presidente Antonio Carlos LTDA., ITPAC-Porto Nacional S.A., TO, Brazil
| | - Barbara S Moraes
- PROAHSA - Programa de Estudos Avançados em Administração Hospitalar e Sistemas de Saúde, São Paulo, Brazil
| | - Marcelo S da Silva
- Laboratório Especial de Ciclo Celular, Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, SP, Brazil
| | - Camila B Storti
- Genetics Dept., Biosciences Institute, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Marcos R M Fontes
- Biophysics and Physics Dept., Biosciences Institute, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Maria Isabel N Cano
- Genetics Dept., Biosciences Institute, São Paulo State University (UNESP), Botucatu, SP, Brazil.
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da Silva MS, Segatto M, Pavani RS, Gutierrez-Rodrigues F, Bispo VDS, de Medeiros MHG, Calado RT, Elias MC, Cano MIN. Consequences of acute oxidative stress in Leishmania amazonensis : From telomere shortening to the selection of the fittest parasites. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:138-150. [DOI: 10.1016/j.bbamcr.2016.11.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/17/2016] [Accepted: 11/01/2016] [Indexed: 01/08/2023]
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Abstract
Telomerase is the eukaryotic solution to the ‘end-replication problem’ of linear chromosomes by synthesising the highly repetitive DNA constituent of telomeres, the nucleoprotein cap that protects chromosome termini. Functioning as a ribonucleoprotein (RNP) enzyme, telomerase is minimally composed of the highly conserved catalytic telomerase reverse transcriptase (TERT) and essential telomerase RNA (TR) component. Beyond merely providing the template for telomeric DNA synthesis, TR is an innate telomerase component and directly facilitates enzymatic function. TR accomplishes this by having evolved structural elements for stable assembly with the TERT protein and the regulation of the telomerase catalytic cycle. Despite its prominence and prevalence, TR has profoundly diverged in length, sequence, and biogenesis pathway among distinct evolutionary lineages. This diversity has generated numerous structural and mechanistic solutions for ensuring proper RNP formation and high fidelity telomeric DNA synthesis. Telomerase provides unique insights into RNA and protein coevolution within RNP enzymes.
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Affiliation(s)
- Joshua D Podlevsky
- a School of Molecular Sciences, Arizona State University , Tempe , AZ , USA
| | - Julian J-L Chen
- a School of Molecular Sciences, Arizona State University , Tempe , AZ , USA
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