1
|
Musmaker K, Wells J, Tsai MC, Comeron JM, Malkova A. Alternative Lengthening of Telomeres in Yeast: Old Questions and New Approaches. Biomolecules 2024; 14:113. [PMID: 38254712 PMCID: PMC10813009 DOI: 10.3390/biom14010113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
Alternative lengthening of telomeres (ALT) is a homologous recombination-based pathway utilized by 10-15% of cancer cells that allows cells to maintain their telomeres in the absence of telomerase. This pathway was originally discovered in the yeast Saccharomyces cerevisiae and, for decades, yeast has served as a robust model to study ALT. Using yeast as a model, two types of ALT (RAD51-dependent and RAD51-independent) have been described. Studies in yeast have provided the phenotypic characterization of ALT survivors, descriptions of the proteins involved, and implicated break-induced replication (BIR) as the mechanism responsible for ALT. Nevertheless, many questions have remained, and answering them has required the development of new quantitative methods. In this review we discuss the historic aspects of the ALT investigation in yeast as well as new approaches to investigating ALT, including ultra-long sequencing, computational modeling, and the use of population genetics. We discuss how employing new methods contributes to our current understanding of the ALT mechanism and how they may expand our understanding of ALT in the future.
Collapse
Affiliation(s)
- Kendra Musmaker
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA (J.W.)
| | - Jacob Wells
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA (J.W.)
| | - Meng-Chia Tsai
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA (J.W.)
| | - Josep M. Comeron
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA (J.W.)
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA 52242, USA
| | - Anna Malkova
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA (J.W.)
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA 52242, USA
| |
Collapse
|
2
|
Hao J, Wang X, Shi Y, Li L, Chu J, Li J, Lin W, Yu T, Hou D. Integrated omic profiling of the medicinal mushroom Inonotus obliquus under submerged conditions. BMC Genomics 2023; 24:554. [PMID: 37726686 PMCID: PMC10507853 DOI: 10.1186/s12864-023-09656-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 09/06/2023] [Indexed: 09/21/2023] Open
Abstract
BACKGROUND The Inonotus obliquus mushroom, a wondrous fungus boasting edible and medicinal qualities, has been widely used as a folk medicine and shown to have many potential pharmacological secondary metabolites. The purpose of this study was to supply a global landscape of genome-based integrated omic analysis of the fungus under lab-growth conditions. RESULTS This study presented a genome with high accuracy and completeness using the Pacbio Sequel II third-generation sequencing method. The de novo assembled fungal genome was 36.13 Mb, and contained 8352 predicted protein-coding genes, of which 365 carbohydrate-active enzyme (CAZyme)-coding genes and 19 biosynthetic gene clusters (BCGs) for secondary metabolites were identified. Comparative transcriptomic and proteomic analysis revealed a global view of differential metabolic change between seed and fermentation culture, and demonstrated positive correlations between transcription and expression levels of 157 differentially expressed genes involved in the metabolism of amino acids, fatty acids, secondary metabolites, antioxidant and immune responses. Facilitated by the widely targeted metabolomic approach, a total of 307 secondary substances were identified and quantified, with a significant increase in the production of antioxidant polyphenols. CONCLUSION This study provided the comprehensive analysis of the fungus Inonotus obliquus, and supplied fundamental information for further screening of promising target metabolites and exploring the link between the genome and metabolites.
Collapse
Affiliation(s)
- Jinghua Hao
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Xiaoli Wang
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Yanhua Shi
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Lingjun Li
- School of Modern Agriculture and Environment, Weifang Institute of Technology, Weifang, 261053, China
| | - Jinxin Chu
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Junjie Li
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Weiping Lin
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China.
| | - Tao Yu
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China.
| | - Dianhai Hou
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China.
| |
Collapse
|
3
|
Xiong Y, Zhang H, Zhou S, Ma L, Xiao W, Wu Y, Yuan YJ. Structural Variations and Adaptations of Synthetic Chromosome Ends Driven by SCRaMbLE in Haploid and Diploid Yeasts. ACS Synth Biol 2023; 12:689-699. [PMID: 36821394 DOI: 10.1021/acssynbio.2c00424] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Variations and adaptations of chromosome ends play an important role in eukaryotic karyotype evolution. Traditional experimental studies of the adaptations of chromosome ends mainly rely on the strategy of introducing defects; thus, the adaptation methods of survivors may vary depending on the initial defects. Here, using the SCRaMbLE strategy, we obtained a library of haploid and diploid synthetic strains with variations in chromosome ends. Analysis of the SCRaMbLEd survivors revealed four routes of adaptation: homologous recombination between nonhomologous chromosome arms (haploids) or homologous chromosome arms (diploids), site-specific recombination between intra- or interchromosomal ends, circularization of chromosomes, and loss of whole chromosomes (diploids). We also found that circularization of synthetic chromosomes can be generated by SCRaMbLE. Our study of various adaptation routes of chromosome ends provides insight into eukaryotic karyotype evolution from the viewpoint of synthetic genomics.
Collapse
Affiliation(s)
- Yao Xiong
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Hui Zhang
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Sijie Zhou
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Lu Ma
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Wenhai Xiao
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yi Wu
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Ying-Jin Yuan
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| |
Collapse
|
4
|
D’Angiolo M, Yue JX, De Chiara M, Barré BP, Giraud Panis MJ, Gilson E, Liti G. Telomeres are shorter in wild Saccharomyces cerevisiae isolates than in domesticated ones. Genetics 2023; 223:iyac186. [PMID: 36563016 PMCID: PMC9991508 DOI: 10.1093/genetics/iyac186] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/02/2022] [Accepted: 12/03/2022] [Indexed: 12/24/2022] Open
Abstract
Telomeres are ribonucleoproteins that cap chromosome-ends and their DNA length is controlled by counteracting elongation and shortening processes. The budding yeast Saccharomyces cerevisiae has been a leading model to study telomere DNA length control and dynamics. Its telomeric DNA is maintained at a length that slightly varies between laboratory strains, but little is known about its variation at the species level. The recent publication of the genomes of over 1,000 S. cerevisiae strains enabled us to explore telomere DNA length variation at an unprecedented scale. Here, we developed a bioinformatic pipeline (YeaISTY) to estimate telomere DNA length from whole-genome sequences and applied it to the sequenced S. cerevisiae collection. Our results revealed broad natural telomere DNA length variation among the isolates. Notably, telomere DNA length is shorter in those derived from wild rather than domesticated environments. Moreover, telomere DNA length variation is associated with mitochondrial metabolism, and this association is driven by wild strains. Overall, these findings reveal broad variation in budding yeast's telomere DNA length regulation, which might be shaped by its different ecological life-styles.
Collapse
Affiliation(s)
- Melania D’Angiolo
- Institute for Research on Cancer and Aging (IRCAN), Université Côte d’Azur, 28 Avenue de Valombrose, 06107 Nice, France
| | - Jia-Xing Yue
- Institute for Research on Cancer and Aging (IRCAN), Université Côte d’Azur, 28 Avenue de Valombrose, 06107 Nice, France
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center (SYSUCC), 651 Dongfeng Road East, China
| | - Matteo De Chiara
- Institute for Research on Cancer and Aging (IRCAN), Université Côte d’Azur, 28 Avenue de Valombrose, 06107 Nice, France
| | - Benjamin P Barré
- Institute for Research on Cancer and Aging (IRCAN), Université Côte d’Azur, 28 Avenue de Valombrose, 06107 Nice, France
| | - Marie-Josèphe Giraud Panis
- Institute for Research on Cancer and Aging (IRCAN), Université Côte d’Azur, 28 Avenue de Valombrose, 06107 Nice, France
| | - Eric Gilson
- Institute for Research on Cancer and Aging (IRCAN), Université Côte d’Azur, 28 Avenue de Valombrose, 06107 Nice, France
- Department of Genetics, CHU, 06107 Nice, France
| | - Gianni Liti
- Institute for Research on Cancer and Aging (IRCAN), Université Côte d’Azur, 28 Avenue de Valombrose, 06107 Nice, France
| |
Collapse
|
5
|
Abstract
Inheriting the wrong number of chromosomes is one of the leading causes of infertility and birth defects in humans. However, in many organisms, individual chromosomes vary dramatically in both organization, sequence, and size. Chromosome segregation systems must be capable of accounting for these differences to reliably segregate chromosomes. During gametogenesis, meiosis ensures that all chromosomes segregate properly into gametes (i.e., egg or sperm). Interestingly, not all chromosomes exhibit the same dynamics during meiosis, which can lead to chromosome-specific behaviors and defects. This review will summarize some of the chromosome-specific meiotic events that are currently known and discuss their impact on meiotic outcomes.
Collapse
|
6
|
Peska V, Fajkus P, Bubeník M, Brázda V, Bohálová N, Dvořáček V, Fajkus J, Garcia S. Extraordinary diversity of telomeres, telomerase RNAs and their template regions in Saccharomycetaceae. Sci Rep 2021; 11:12784. [PMID: 34140564 PMCID: PMC8211666 DOI: 10.1038/s41598-021-92126-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/03/2021] [Indexed: 01/08/2023] Open
Abstract
Telomerase RNA (TR) carries the template for synthesis of telomere DNA and provides a scaffold for telomerase assembly. Fungal TRs are long and have been compared to higher eukaryotes, where they show considerable diversity within phylogenetically close groups. TRs of several Saccharomycetaceae were recently identified, however, many of these remained uncharacterised in the template region. Here we show that this is mainly due to high variability in telomere sequence. We predicted the telomere sequences using Tandem Repeats Finder and then we identified corresponding putative template regions in TR candidates. Remarkably long telomere units and the corresponding putative TRs were found in Tetrapisispora species. Notably, variable lengths of the annealing sequence of the template region (1–10 nt) were found. Consequently, species with the same telomere sequence may not harbour identical TR templates. Thus, TR sequence alone can be used to predict a template region and telomere sequence, but not to determine these exactly. A conserved feature of telomere sequences, tracts of adjacent Gs, led us to test the propensity of individual telomere sequences to form G4. The results show highly diverse values of G4-propensity, indicating the lack of ubiquitous conservation of this feature across Saccharomycetaceae.
Collapse
Affiliation(s)
- Vratislav Peska
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.
| | - Petr Fajkus
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, 62500, Czech Republic
| | - Michal Bubeník
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, 62500, Czech Republic
| | - Václav Brázda
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic
| | - Natália Bohálová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.,Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, 62500, Czech Republic
| | - Vojtěch Dvořáček
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic
| | - Jiří Fajkus
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, 62500, Czech Republic
| | - Sònia Garcia
- Institut Botànic de Barcelona (IBB-CSIC, Ajuntament de Barcelona), Passeig del Migdia s/n, 08038, Barcelona, Catalonia, Spain.
| |
Collapse
|
7
|
Pinheiro Figliuolo VS, Ferreira AMV, Guimarães EMC, de Sousa E Souza JF, Feldberg E, Gross MC. Cryptic Diversity in the Terminal Portion of the Chromosomes of the Dogtooth Characins, Family Cynodontidae (Ostariophysi: Characiformes). Zebrafish 2021; 18:221-230. [PMID: 33847525 DOI: 10.1089/zeb.2020.1973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The chromosomes of the dogtooth characins, fish species of the family Cynodontidae, have only a relatively small amount of heterochromatin, including the terminal portion. Curiously, in the cynodontid Cynodon gibbus, the terminal portion is rich in repetitive DNAs, including transposable retroelements and microsatellite sequences. Given this, this study investigated the composition of the terminal portion of the chromosomes of two cynodontid species (Rhaphiodon vulpinus and Hydrolycus armatus), to compile a database for the evaluation of all three cynodontid genera, and in particular, verify the possible tendency for the accumulation of repetitive DNAs in the terminal portion of the chromosomes of C. gibbus, H. armatus, and R. vulpinus. The Rex1, Rex3, and Rex6 transposable retroelements and the (CA)15, (GA)15, (GATA)8, (GACA)8, (CAT)10, and (CAC)10 microsatellite motifs are found primarily in the terminal portion of the chromosomes of the species analyzed in this study, except R. vulpinus, which has no evidence of the presence of Rex1 or Rex3 through the fluorescent in situ hybridization technique. The mapping of the repetitive sequences, principally the microsatellite motifs, indicates a marked tendency for the accumulation of these sequences in the terminal portions of the chromosomes, which may have played a fundamental role in the differentiation of the three species.
Collapse
Affiliation(s)
| | | | | | | | - Eliana Feldberg
- Laboratory of Animal Genetics, National Institute of Amazonian Research (INPA), Manaus, Brazil
| | - Maria Claudia Gross
- Institute for Natural and Life Sciences, Federal University of Latin American Integration, Foz do Iguaçu, Brazil
| |
Collapse
|
8
|
Saint-Leandre B, Levine MT. The Telomere Paradox: Stable Genome Preservation with Rapidly Evolving Proteins. Trends Genet 2020; 36:232-242. [PMID: 32155445 DOI: 10.1016/j.tig.2020.01.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 01/08/2020] [Accepted: 01/13/2020] [Indexed: 01/08/2023]
Abstract
Telomeres ensure chromosome length homeostasis and protection from catastrophic end-to-end chromosome fusions. All eukaryotes require this essential, strictly conserved telomere-dependent genome preservation. However, recent evolutionary analyses of mammals, plants, and flies report pervasive rapid evolution of telomere proteins. The causes of this paradoxical observation - that unconserved machinery underlies an essential, conserved function - remain enigmatic. Indeed, these fast-evolving telomere proteins bind, extend, and protect telomeric DNA, which itself evolves slowly in most systems. We hypothesize that the universally fast-evolving subtelomere - the telomere-adjacent, repetitive sequence - is a primary driver of the 'telomere paradox'. Under this model, radical sequence changes in the subtelomere perturb subtelomere-dependent, telomere functions. Compromised telomere function then spurs adaptation of telomere proteins to maintain telomere length homeostasis and protection. We propose an experimental framework that leverages both protein divergence and subtelomeric sequence divergence to test the hypothesis that subtelomere sequence evolution shapes recurrent innovation of telomere machinery.
Collapse
Affiliation(s)
- Bastien Saint-Leandre
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Mia T Levine
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
9
|
Aksenova AY, Mirkin SM. At the Beginning of the End and in the Middle of the Beginning: Structure and Maintenance of Telomeric DNA Repeats and Interstitial Telomeric Sequences. Genes (Basel) 2019; 10:genes10020118. [PMID: 30764567 PMCID: PMC6410037 DOI: 10.3390/genes10020118] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 01/30/2019] [Accepted: 01/30/2019] [Indexed: 02/07/2023] Open
Abstract
Tandem DNA repeats derived from the ancestral (TTAGGG)n run were first detected at chromosome ends of the majority of living organisms, hence the name telomeric DNA repeats. Subsequently, it has become clear that telomeric motifs are also present within chromosomes, and they were suitably called interstitial telomeric sequences (ITSs). It is well known that telomeric DNA repeats play a key role in chromosome stability, preventing end-to-end fusions and precluding the recurrent DNA loss during replication. Recent data suggest that ITSs are also important genomic elements as they confer its karyotype plasticity. In fact, ITSs appeared to be among the most unstable microsatellite sequences as they are highly length polymorphic and can trigger chromosomal fragility and gross chromosomal rearrangements. Importantly, mechanisms responsible for their instability appear to be similar to the mechanisms that maintain the length of genuine telomeres. This review compares the mechanisms of maintenance and dynamic properties of telomeric repeats and ITSs and discusses the implications of these dynamics on genome stability.
Collapse
Affiliation(s)
- Anna Y Aksenova
- Laboratory of Amyloid Biology, St. Petersburg State University, 199034 St. Petersburg, Russia.
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Medford, MA 02421, USA.
| |
Collapse
|
10
|
Rubio‐Magnieto J, Kajouj S, Di Meo F, Fossépré M, Trouillas P, Norman P, Linares M, Moucheron C, Surin M. Binding Modes and Selectivity of Ruthenium Complexes to Human Telomeric DNA G‐Quadruplexes. Chemistry 2018; 24:15577-15588. [DOI: 10.1002/chem.201802147] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 07/12/2018] [Indexed: 02/05/2023]
Affiliation(s)
- Jenifer Rubio‐Magnieto
- Laboratory for Chemistry of Novel Materials Center for Innovation in Materials and Polymers University of Mons-UMONS 20 Place du Parc 7000 Mons Belgium
- Current address: Bioinspired Supramolecular Chemistry and Materials group Departament de Química Inorgànica i Orgànica Universitat Jaume I Avda Sos Baynat s/n E-12071 Castelló Spain
| | - Sofia Kajouj
- Chimie Organique et Photochimie CP160/08 Université libre de Bruxelles 50 avenue F. D. Roosevelt 1050 Bruxelles Belgium
| | - Florent Di Meo
- INSERM U1248 IPPRITT University of Limoges School of Pharmacy 2 rue du Dr. Marcland 87025 Limoges France
| | - Mathieu Fossépré
- Laboratory for Chemistry of Novel Materials Center for Innovation in Materials and Polymers University of Mons-UMONS 20 Place du Parc 7000 Mons Belgium
| | - Patrick Trouillas
- INSERM U1248 IPPRITT University of Limoges School of Pharmacy 2 rue du Dr. Marcland 87025 Limoges France
- RCPTM Palacký University Faculty of Sciences Šlechtitelů 27 78371 Olomouc Czech Republic
| | - Patrick Norman
- Department of Theoretical Chemistry and Biology School of Engineering Sciences in Chemistry Biotechnology and Health KTH Royal Institute of Technology SE-106 91 Stockholm Sweden
| | - Mathieu Linares
- Department of Theoretical Chemistry and Biology School of Engineering Sciences in Chemistry Biotechnology and Health KTH Royal Institute of Technology SE-106 91 Stockholm Sweden
- Swedish e-Science Research Centre (SeRC) KTH Royal Institute of Technology 104 50 Stockholm Sweden
| | - Cécile Moucheron
- Chimie Organique et Photochimie CP160/08 Université libre de Bruxelles 50 avenue F. D. Roosevelt 1050 Bruxelles Belgium
| | - Mathieu Surin
- Laboratory for Chemistry of Novel Materials Center for Innovation in Materials and Polymers University of Mons-UMONS 20 Place du Parc 7000 Mons Belgium
| |
Collapse
|
11
|
Waldl M, Thiel BC, Ochsenreiter R, Holzenleiter A, de Araujo Oliveira JV, Walter MEMT, Wolfinger MT, Stadler PF. TERribly Difficult: Searching for Telomerase RNAs in Saccharomycetes. Genes (Basel) 2018; 9:genes9080372. [PMID: 30049970 PMCID: PMC6115765 DOI: 10.3390/genes9080372] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/17/2018] [Accepted: 07/18/2018] [Indexed: 11/20/2022] Open
Abstract
The telomerase RNA in yeasts is large, usually >1000 nt, and contains functional elements that have been extensively studied experimentally in several disparate species. Nevertheless, they are very difficult to detect by homology-based methods and so far have escaped annotation in the majority of the genomes of Saccharomycotina. This is a consequence of sequences that evolve rapidly at nucleotide level, are subject to large variations in size, and are highly plastic with respect to their secondary structures. Here, we report on a survey that was aimed at closing this gap in RNA annotation. Despite considerable efforts and the combination of a variety of different methods, it was only partially successful. While 27 new telomerase RNAs were identified, we had to restrict our efforts to the subgroup Saccharomycetacea because even this narrow subgroup was diverse enough to require different search models for different phylogenetic subgroups. More distant branches of the Saccharomycotina remain without annotated telomerase RNA.
Collapse
Affiliation(s)
- Maria Waldl
- Institute for Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Wien, Austria.
| | - Bernhard C Thiel
- Institute for Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Wien, Austria.
| | - Roman Ochsenreiter
- Institute for Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Wien, Austria.
| | - Alexander Holzenleiter
- BioInformatics Group, Fakultät CB Hochschule Mittweida, Technikumplatz 17, D-09648 Mittweida, Germany.
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany.
| | - João Victor de Araujo Oliveira
- Departamento de Ciência da Computação, Instituto de Ciências Exatas, Universidade de Brasília, Campus Universitário⁻Asa Norte, Brasília, DF CEP: 70910-900, Brazil.
| | - Maria Emília M T Walter
- Departamento de Ciência da Computação, Instituto de Ciências Exatas, Universidade de Brasília, Campus Universitário⁻Asa Norte, Brasília, DF CEP: 70910-900, Brazil.
| | - Michael T Wolfinger
- Institute for Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Wien, Austria.
- Center for Anatomy and Cell Biology, Medical University of Vienna, Währingerstraße 13, 1090 Vienna, Austria.
| | - Peter F Stadler
- Institute for Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Wien, Austria.
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Competence Center for Scalable Data Services and Solutions, and Leipzig Research Center for Civilization Diseases, Universität Leipzig, D-04107 Leipzig, Germany.
- Max Planck Institute for Mathematics in the Sciences, Inselstraße 22, D-04103 Leipzig, Germany.
- Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA.
| |
Collapse
|
12
|
Hsu M, Lue NF. Analysis of Yeast Telomerase by Primer Extension Assays. Methods Mol Biol 2018; 1587:83-93. [PMID: 28324500 DOI: 10.1007/978-1-4939-6892-3_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Telomeres are specialized nucleoprotein structures located at eukaryotic chromosomal termini, which are required for chromosome stability and are maintained by a reverse transcriptase named telomerase. Budding yeast has served as an extremely useful model system for analyzing telomere maintenance because the organism offers a wide range of genetic and biochemical tools. Several milestones in telomerase research have been reached through investigation of the yeast system. For example, the consequence of telomerase loss was first characterized in the budding yeast Saccharomyces cerevisiae. The catalytic component of telomerase (telomerase reverse transcriptase; TERT) was likewise initially cloned from this organism. Moreover, much of the current understanding of the structure and function of the telomerase complex was derived from yeast studies. In this chapter, we discuss one of the most useful tools for investigating yeast telomerase mechanisms and regulation: the primer extension assay. This assay can be used to examine the overall activity as well as the processivity of telomerase, which represents a unique aspect of telomerase enzymology. It can also be employed to analyze the mechanisms of telomerase regulatory proteins.
Collapse
Affiliation(s)
- Min Hsu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10021, USA
| | - Neal F Lue
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY, 10021, USA.
| |
Collapse
|
13
|
Lin R, Qin F, Shen B, Shi Q, Liu C, Zhang X, Jiao Y, Lu J, Gao Y, Suarez-Fernandez M, Lopez-Moya F, Lopez-Llorca LV, Wang G, Mao Z, Ling J, Yang Y, Cheng X, Xie B. Genome and secretome analysis of Pochonia chlamydosporia provide new insight into egg-parasitic mechanisms. Sci Rep 2018; 8:1123. [PMID: 29348510 PMCID: PMC5773674 DOI: 10.1038/s41598-018-19169-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 12/22/2017] [Indexed: 11/24/2022] Open
Abstract
Pochonia chlamydosporia infects eggs and females of economically important plant-parasitic nematodes. The fungal isolates parasitizing different nematodes are genetically distinct. To understand their intraspecific genetic differentiation, parasitic mechanisms, and adaptive evolution, we assembled seven putative chromosomes of P. chlamydosporia strain 170 isolated from root-knot nematode eggs (~44 Mb, including 7.19% of transposable elements) and compared them with the genome of the strain 123 (~41 Mb) isolated from cereal cyst nematode. We focus on secretomes of the fungus, which play important roles in pathogenicity and fungus-host/environment interactions, and identified 1,750 secreted proteins, with a high proportion of carboxypeptidases, subtilisins, and chitinases. We analyzed the phylogenies of these genes and predicted new pathogenic molecules. By comparative transcriptome analysis, we found that secreted proteins involved in responses to nutrient stress are mainly comprised of proteases and glycoside hydrolases. Moreover, 32 secreted proteins undergoing positive selection and 71 duplicated gene pairs encoding secreted proteins are identified. Two duplicated pairs encoding secreted glycosyl hydrolases (GH30), which may be related to fungal endophytic process and lost in many insect-pathogenic fungi but exist in nematophagous fungi, are putatively acquired from bacteria by horizontal gene transfer. The results help understanding genetic origins and evolution of parasitism-related genes.
Collapse
Affiliation(s)
- Runmao Lin
- College of Life Sciences, Beijing Normal University, Beijing, China.,Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Feifei Qin
- College of Life Sciences, Beijing Normal University, Beijing, China.,Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Baoming Shen
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qianqian Shi
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Chichuan Liu
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xi Zhang
- College of Life Sciences, Beijing Normal University, Beijing, China.,Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yang Jiao
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jun Lu
- College of Life Sciences, Beijing Normal University, Beijing, China
| | - Yaoyao Gao
- College of Life Sciences, Beijing Normal University, Beijing, China
| | - Marta Suarez-Fernandez
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, University of Alicante, Alicante, Spain
| | - Federico Lopez-Moya
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, University of Alicante, Alicante, Spain
| | - Luis Vicente Lopez-Llorca
- Laboratory of Plant Pathology, Department of Marine Sciences and Applied Biology, University of Alicante, Alicante, Spain
| | - Gang Wang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhenchuan Mao
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jian Ling
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuhong Yang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xinyue Cheng
- College of Life Sciences, Beijing Normal University, Beijing, China. .,Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Beijing, China.
| | - Bingyan Xie
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China. .,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Beijing, China.
| |
Collapse
|
14
|
Tkavc R, Matrosova VY, Grichenko OE, Gostinčar C, Volpe RP, Klimenkova P, Gaidamakova EK, Zhou CE, Stewart BJ, Lyman MG, Malfatti SA, Rubinfeld B, Courtot M, Singh J, Dalgard CL, Hamilton T, Frey KG, Gunde-Cimerman N, Dugan L, Daly MJ. Prospects for Fungal Bioremediation of Acidic Radioactive Waste Sites: Characterization and Genome Sequence of Rhodotorula taiwanensis MD1149. Front Microbiol 2018; 8:2528. [PMID: 29375494 PMCID: PMC5766836 DOI: 10.3389/fmicb.2017.02528] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 12/05/2017] [Indexed: 02/03/2023] Open
Abstract
Highly concentrated radionuclide waste produced during the Cold War era is stored at US Department of Energy (DOE) production sites. This radioactive waste was often highly acidic and mixed with heavy metals, and has been leaking into the environment since the 1950s. Because of the danger and expense of cleanup of such radioactive sites by physicochemical processes, in situ bioremediation methods are being developed for cleanup of contaminated ground and groundwater. To date, the most developed microbial treatment proposed for high-level radioactive sites employs the radiation-resistant bacterium Deinococcus radiodurans. However, the use of Deinococcus spp. and other bacteria is limited by their sensitivity to low pH. We report the characterization of 27 diverse environmental yeasts for their resistance to ionizing radiation (chronic and acute), heavy metals, pH minima, temperature maxima and optima, and their ability to form biofilms. Remarkably, many yeasts are extremely resistant to ionizing radiation and heavy metals. They also excrete carboxylic acids and are exceptionally tolerant to low pH. A special focus is placed on Rhodotorula taiwanensis MD1149, which was the most resistant to acid and gamma radiation. MD1149 is capable of growing under 66 Gy/h at pH 2.3 and in the presence of high concentrations of mercury and chromium compounds, and forming biofilms under high-level chronic radiation and low pH. We present the whole genome sequence and annotation of R. taiwanensis strain MD1149, with a comparison to other Rhodotorula species. This survey elevates yeasts to the frontier of biology's most radiation-resistant representatives, presenting a strong rationale for a role of fungi in bioremediation of acidic radioactive waste sites.
Collapse
Affiliation(s)
- Rok Tkavc
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Vera Y Matrosova
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Olga E Grichenko
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Cene Gostinčar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Robert P Volpe
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Polina Klimenkova
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Elena K Gaidamakova
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Carol E Zhou
- Lawrence Livermore National Laboratory, Computing Applications and Research Department, Livermore, CA, United States
| | - Benjamin J Stewart
- Biosciences and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Mathew G Lyman
- Biosciences and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Stephanie A Malfatti
- Biosciences and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Bonnee Rubinfeld
- Biosciences and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Melanie Courtot
- European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, United Kingdom
| | - Jatinder Singh
- Collaborative Health Initiative Research Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Clifton L Dalgard
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,The American Genome Center, Bethesda, MD, United States
| | - Theron Hamilton
- Biological Defense Research Directorate, Naval Medical Research Center, Fredrick, MD, United States
| | - Kenneth G Frey
- Biological Defense Research Directorate, Naval Medical Research Center, Fredrick, MD, United States
| | - Nina Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Lawrence Dugan
- Biosciences and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Michael J Daly
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| |
Collapse
|
15
|
Bellasio M, Peymann A, Steiger MG, Valli M, Sipiczki M, Sauer M, Graf AB, Marx H, Mattanovich D. Complete genome sequence and transcriptome regulation of the pentose utilizing yeastSugiyamaella lignohabitans. FEMS Yeast Res 2016; 16:fow037. [DOI: 10.1093/femsyr/fow037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2016] [Indexed: 01/17/2023] Open
|
16
|
Casas-Vila N, Scheibe M, Freiwald A, Kappei D, Butter F. Identification of TTAGGG-binding proteins in Neurospora crassa, a fungus with vertebrate-like telomere repeats. BMC Genomics 2015; 16:965. [PMID: 26577093 PMCID: PMC4650311 DOI: 10.1186/s12864-015-2158-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 10/27/2015] [Indexed: 11/23/2022] Open
Abstract
Background To date, telomere research in fungi has mainly focused on Saccharomyces cerevisiae and Schizosaccharomyces pombe, despite the fact that both yeasts have degenerated telomeric repeats in contrast to the canonical TTAGGG motif found in vertebrates and also several other fungi. Results Using label-free quantitative proteomics, we here investigate the telosome of Neurospora crassa, a fungus with canonical telomeric repeats. We show that at least six of the candidates detected in our screen are direct TTAGGG-repeat binding proteins. While three of the direct interactors (NCU03416 [ncTbf1], NCU01991 [ncTbf2] and NCU02182 [ncTay1]) feature the known myb/homeobox DNA interaction domain also found in the vertebrate telomeric factors, we additionally show that a zinc-finger protein (NCU07846) and two proteins without any annotated DNA-binding domain (NCU02644 and NCU05718) are also direct double-strand TTAGGG binders. We further find two single-strand binders (NCU02404 [ncGbp2] and NCU07735 [ncTcg1]). Conclusion By quantitative label-free interactomics we identify TTAGGG-binding proteins in Neurospora crassa, suggesting candidates for telomeric factors that are supported by phylogenomic comparison with yeast species. Intriguingly, homologs in yeast species with degenerated telomeric repeats are also TTAGGG-binding proteins, e.g. in S. cerevisiae Tbf1 recognizes the TTAGGG motif found in its subtelomeres. However, there is also a subset of proteins that is not conserved. While a rudimentary core TTAGGG-recognition machinery may be conserved across yeast species, our data suggests Neurospora as an emerging model organism with unique features. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2158-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Núria Casas-Vila
- Quantitative Proteomics, Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128, Mainz, Germany
| | - Marion Scheibe
- Quantitative Proteomics, Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128, Mainz, Germany
| | - Anja Freiwald
- Quantitative Proteomics, Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128, Mainz, Germany
| | - Dennis Kappei
- Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, 117599, Singapore, Singapore
| | - Falk Butter
- Quantitative Proteomics, Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128, Mainz, Germany.
| |
Collapse
|
17
|
Wendland J, Walther A. Chromosome number reduction in Eremothecium coryli by two telomere-to-telomere fusions. Genome Biol Evol 2014; 6:1186-98. [PMID: 24803574 PMCID: PMC4040997 DOI: 10.1093/gbe/evu089] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/27/2014] [Indexed: 11/16/2022] Open
Abstract
The genus Eremothecium belongs to the Saccharomyces complex of pre-whole-genome duplication (WGD) yeasts and contains both dimorphic and filamentous species. We established the 9.1-Mb draft genome of Eremothecium coryli, which encodes 4,682 genes, 186 tRNA genes, and harbors several Ty3 transposons as well as more than 60 remnants of transposition events (LTRs). The initial de novo assembly resulted in 19 scaffolds, which were assembled based on synteny to other Eremothecium genomes into six chromosomes. Interestingly, we identified eight E. coryli loci that bear centromeres in the closely related species E. cymbalariae. Two of these E. coryli loci, CEN1 and CEN8, however, lack conserved DNA elements and did not convey centromere function in a plasmid stability assay. Correspondingly, using a comparative genomics approach we identified two telomere-to-telomere fusion events in E. coryli as the cause of chromosome number reduction from eight to six chromosomes. Finally, with the genome sequences of E. coryli, E. cymbalariae, and Ashbya gossypii a reconstruction of three complete chromosomes of an Eremothecium ancestor revealed that E. coryli is more syntenic to this ancestor than the other Eremothecium species.
Collapse
Affiliation(s)
| | - Andrea Walther
- Carlsberg Laboratory, Yeast Biology, Copenhagen, Denmark
| |
Collapse
|
18
|
Garavís M, González C, Villasante A. On the origin of the eukaryotic chromosome: the role of noncanonical DNA structures in telomere evolution. Genome Biol Evol 2013; 5:1142-50. [PMID: 23699225 PMCID: PMC3698924 DOI: 10.1093/gbe/evt079] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The transition of an ancestral circular genome to multiple linear chromosomes was crucial for eukaryogenesis because it allowed rapid adaptive evolution through aneuploidy. Here, we propose that the ends of nascent linear chromosomes should have had a dual function in chromosome end protection (capping) and chromosome segregation to give rise to the “proto-telomeres.” Later on, proper centromeres evolved at subtelomeric regions. We also propose that both noncanonical structures based on guanine–guanine interactions and the end-protection proteins recruited by the emergent telomeric heterochromatin have been required for telomere maintenance through evolution. We further suggest that the origin of Drosophila telomeres may be reminiscent of how the first telomeres arose.
Collapse
Affiliation(s)
- Miguel Garavís
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
| | | | | |
Collapse
|
19
|
Fulnecková J, Sevcíková T, Fajkus J, Lukesová A, Lukes M, Vlcek C, Lang BF, Kim E, Eliás M, Sykorová E. A broad phylogenetic survey unveils the diversity and evolution of telomeres in eukaryotes. Genome Biol Evol 2013; 5:468-83. [PMID: 23395982 PMCID: PMC3622300 DOI: 10.1093/gbe/evt019] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Telomeres, ubiquitous and essential structures of eukaryotic chromosomes, are known to come in a variety of forms, but knowledge about their actual diversity and evolution across the whole phylogenetic breadth of the eukaryotic life remains fragmentary. To fill this gap, we employed a complex experimental approach to probe telomeric minisatellites in various phylogenetically diverse groups of algae. Our most remarkable results include the following findings: 1) algae of the streptophyte class Klebsormidiophyceae possess the Chlamydomonas-type telomeric repeat (TTTTAGGG) or, in at least one species, a novel TTTTAGG repeat, indicating an evolutionary transition from the Arabidopsis-type repeat (TTTAGGG) ancestral for Chloroplastida; 2) the Arabidopsis-type repeat is also present in telomeres of Xanthophyceae, in contrast to the presence of the human-type repeat (TTAGGG) in other ochrophytes studied, and of the photosynthetic alveolate Chromera velia, consistent with its phylogenetic position close to apicomplexans and dinoflagellates; 3) glaucophytes and haptophytes exhibit the human-type repeat in their telomeres; and 4) ulvophytes and rhodophytes have unusual telomere structures recalcitrant to standard analysis. To obtain additional details on the distribution of different telomere types in eukaryotes, we performed in silico analyses of genomic data from major eukaryotic lineages, utilizing also genome assemblies from our on-going genome projects for representatives of three hitherto unsampled lineages (jakobids, malawimonads, and goniomonads). These analyses confirm the human-type repeat as the most common and possibly ancestral in eukaryotes, but alternative motifs replaced it along the phylogeny of diverse eukaryotic lineages, some of them several times independently.
Collapse
Affiliation(s)
- Jana Fulnecková
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Di Domenico EG, Mattarocci S, Cimino-Reale G, Parisi P, Cifani N, D'Ambrosio E, Zakian VA, Ascenzioni F. Tel1 and Rad51 are involved in the maintenance of telomeres with capping deficiency. Nucleic Acids Res 2013; 41:6490-500. [PMID: 23677619 PMCID: PMC3711455 DOI: 10.1093/nar/gkt365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Vertebrate-like T2AG3 telomeres in tlc1-h yeast consist of short double-stranded regions and long single-stranded overhang (G-tails) and, although based on Tbf1-capping activity, they are capping deficient. Consistent with this idea, we observe Y' amplification because of homologous recombination, even in the presence of an active telomerase. In these cells, Y' amplification occurs by different pathways: in Tel1(+) tlc1h cells, it is Rad51-dependent, whereas in the absence of Tel1, it depends on Rad50. Generation of telomeric G-tail, which is cell cycle regulated, depends on the MRX (Mre11-Rad50-Xrs2) complex in tlc1h cells or is MRX-independent in tlc1h tel1Δ mutants. Unexpectedly, we observe telomere elongation in tlc1h lacking Rad51 that seems to act as a telomerase competitor for binding to telomeric G-tails. Overall, our results show that Tel1 and Rad51 have multiple roles in the maintenance of vertebrate-like telomeres in yeast, supporting the idea that they may participate to evolutionary conserved telomere protection mechanism/s acting at uncapped telomeres.
Collapse
Affiliation(s)
- Enea Gino Di Domenico
- Dipartimento di Biologia e Biotecnologie 'Charles Darwin', Sapienza Università di Roma, 00185 Rome, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Teixeira MT. Saccharomyces cerevisiae as a Model to Study Replicative Senescence Triggered by Telomere Shortening. Front Oncol 2013; 3:101. [PMID: 23638436 PMCID: PMC3636481 DOI: 10.3389/fonc.2013.00101] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/11/2013] [Indexed: 01/22/2023] Open
Abstract
In many somatic human tissues, telomeres shorten progressively because of the DNA-end replication problem. Consequently, cells cease to proliferate and are maintained in a metabolically viable state called replicative senescence. These cells are characterized by an activation of DNA damage checkpoints stemming from eroded telomeres, which are bypassed in many cancer cells. Hence, replicative senescence has been considered one of the most potent tumor suppressor pathways. However, the mechanism through which short telomeres trigger this cellular response is far from being understood. When telomerase is removed experimentally in Saccharomyces cerevisiae, telomere shortening also results in a gradual arrest of population growth, suggesting that replicative senescence also occurs in this unicellular eukaryote. In this review, we present the key steps that have contributed to the understanding of the mechanisms underlying the establishment of replicative senescence in budding yeast. As in mammals, signals stemming from short telomeres activate the DNA damage checkpoints, suggesting that the early cellular response to the shortest telomere(s) is conserved in evolution. Yet closer analysis reveals a complex picture in which the apparent single checkpoint response may result from a variety of telomeric alterations expressed in the absence of telomerase. Accordingly, the DNA replication of eroding telomeres appears as a critical challenge for senescing budding yeast cells and the easy manipulation of S. cerevisiae is providing insights into the way short telomeres are integrated into their chromatin and nuclear environments. Finally, the loss of telomerase in budding yeast triggers a more general metabolic alteration that remains largely unexplored. Thus, telomerase-deficient S. cerevisiae cells may have more common points than anticipated with somatic cells, in which telomerase depletion is naturally programed, thus potentially inspiring investigations in mammalian cells.
Collapse
Affiliation(s)
- M Teresa Teixeira
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, FRE3354 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique Paris, France
| |
Collapse
|
22
|
Abstract
Telomerase adds simple-sequence repeats to the ends of linear chromosomes to counteract the loss of end sequence inherent in conventional DNA replication. Catalytic activity for repeat synthesis results from the cooperation of the telomerase reverse transcriptase protein (TERT) and the template-containing telomerase RNA (TER). TERs vary widely in sequence and structure but share a set of motifs required for TERT binding and catalytic activity. Species-specific TER motifs play essential roles in RNP biogenesis, stability, trafficking, and regulation. Remarkably, the biogenesis pathways that generate mature TER differ across eukaryotes. Furthermore, the cellular processes that direct the assembly of a biologically functional telomerase holoenzyme and its engagement with telomeres are evolutionarily varied and regulated. This review highlights the diversity of strategies for telomerase RNP biogenesis, RNP assembly, and telomere recruitment among ciliates, yeasts, and vertebrates and suggests common themes in these pathways and their regulation.
Collapse
Affiliation(s)
- Emily D. Egan
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3200, USA
| | - Kathleen Collins
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3200, USA
- Corresponding authorE-mail
| |
Collapse
|
23
|
Abstract
Telomere DNA-binding proteins protect the ends of chromosomes in eukaryotes. A subset of these proteins are constructed with one or more OB folds and bind with G+T-rich single-stranded DNA found at the extreme termini. The resulting DNA-OB protein complex interacts with other telomere components to coordinate critical telomere functions of DNA protection and DNA synthesis. While the first crystal and NMR structures readily explained protection of telomere ends, the picture of how single-stranded DNA becomes available to serve as primer and template for synthesis of new telomere DNA is only recently coming into focus. New structures of telomere OB fold proteins alongside insights from genetic and biochemical experiments have made significant contributions towards understanding how protein-binding OB proteins collaborate with DNA-binding OB proteins to recruit telomerase and DNA polymerase for telomere homeostasis. This review surveys telomere OB protein structures alongside highly comparable structures derived from replication protein A (RPA) components, with the goal of providing a molecular context for understanding telomere OB protein evolution and mechanism of action in protection and synthesis of telomere DNA.
Collapse
Affiliation(s)
- Martin P Horvath
- Department of Biology, University of Utah, Salt Lake City, Utah 84112-0840, USA.
| |
Collapse
|
24
|
Analyses of Candida Cdc13 orthologues revealed a novel OB fold dimer arrangement, dimerization-assisted DNA binding, and substantial structural differences between Cdc13 and RPA70. Mol Cell Biol 2011; 32:186-98. [PMID: 22025677 DOI: 10.1128/mcb.05875-11] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The budding yeast Cdc13-Stn1-Ten1 complex is crucial for telomere protection and has been proposed to resemble the RPA complex structurally and functionally. The Cdc13 homologues in Candida species are unusually small and lack two conserved domains previously implicated in telomere regulation, thus raising interesting questions concerning the mechanisms and evolution of these proteins. In this report, we show that the unusually small Cdc13 homologue in Candida albicans is indeed a regulator of telomere lengths and that it associates with telomere DNA in vivo. We demonstrated high-affinity telomere DNA binding by C. tropicalis Cdc13 (CtCdc13) and found that dimerization of this protein through its OB4 domain is important for high-affinity DNA binding. Interestingly, CtCdc13-DNA complex formation appears to involve primarily recognition of multiple copies of a six-nucleotide element (GGATGT) that is shared by many Candida telomere repeats. We also determined the crystal structure of the OB4 domain of C. glabrata Cdc13, which revealed a novel mechanism of OB fold dimerization. The structure also exhibits marked differences to the C-terminal OB fold of RPA70, thus arguing against a close evolutionary kinship between these two proteins. Our findings provide new insights on the mechanisms and evolution of a critical telomere end binding protein.
Collapse
|
25
|
Abstract
Telomeres are the nucleoprotein structures at the ends of linear chromosomes and maintain the genomic integrity through multiple cell divisions. Telomeres protect the chromosome ends from degradation, end-to-end fusion and abnormal recombination and they also promote the end replication. The budding yeast Saccharomyces cerevisiae is the most well-studied model system with regard to telomere and telomerase regulation. Recently, the opportunistic fungal pathogen Candida albicans has emerged as an attractive model system for investigating telomere biology. Candida underwent rapid evolutionary divergence with respect to telomere sequences. Concomitant with the evolutionary divergence of telomere sequences, telomere repeat binding factors and telomerase components have also evolved, leading to differences in their functions and domain structures. Thus, the comparative analysis of the telomeres and telomerase-related factors in the budding yeast has provided a better understanding on both conserved and variable aspects of telomere regulation. In this review, I will discuss telomeres and telomerase-related factors and their functions in telomere and telomerase regulation in C. albicans.
Collapse
Affiliation(s)
- Eun Young Yu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Medical College of Cornell University, NY 10065, USA.
| |
Collapse
|
26
|
Ribaud V, Ribeyre C, Damay P, Shore D. DNA-end capping by the budding yeast transcription factor and subtelomeric binding protein Tbf1. EMBO J 2011; 31:138-49. [PMID: 21952045 DOI: 10.1038/emboj.2011.349] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 09/01/2011] [Indexed: 11/09/2022] Open
Abstract
Telomere repeats in budding yeast are maintained at a constant average length and protected ('capped'), in part, by mechanisms involving the TG(1-3) repeat-binding protein Rap1. However, metazoan telomere repeats (T(2)AG(3)) can be maintained in yeast through a Rap1-independent mechanism. Here, we examine the dynamics of capping and telomere formation at an induced DNA double-strand break flanked by varying lengths of T(2)AG(3) repeats. We show that a 60-bp T(2)AG(3) repeat array induces a transient G2/M checkpoint arrest, but is rapidly elongated by telomerase to generate a stable T(2)AG(3)/TG(1-3) hybrid telomere. In contrast, a 230-bp T(2)AG(3) array induces neither G2/M arrest nor telomerase elongation. This capped state requires the T(2)AG(3)-binding protein Tbf1, but is independent of two Tbf1-interacting factors, Vid22 and Ygr071c. Arrays of binding sites for three other subtelomeric or Myb/SANT domain-containing proteins fail to display a similar end-protection effect, indicating that Tbf1 capping is an evolved function. Unexpectedly, we observed strong telomerase association with non-telomeric ends, whose elongation is blocked by a Mec1-dependent mechanism, apparently acting at the level of Cdc13 binding.
Collapse
Affiliation(s)
- Virginie Ribaud
- Department of Molecular Biology, NCCR Program Frontiers in Genetics, University of Geneva, Geneva, Switzerland
| | | | | | | |
Collapse
|
27
|
|
28
|
Abstract
Telomeres are specialized nucleoprotein structures located at eukaryotic chromosomal termini, which are required for chromosome stability and are maintained by a reverse transcriptase named telomerase. Budding yeast has served as an extremely useful model system for analyzing telomere maintenance because the organism offers a wide range of genetic and biochemical tools. Several milestones in telomerase research were reached through investigation of the yeast system. For example, the consequence of telomerase loss was first characterized in the budding yeast Saccharomyces cerevisiae (Lundblad and Szostak, Cell 57:633-643, 1989). The catalytic component of telomerase (telomerase reverse transcriptase; TERT) was likewise initially cloned from this organism (Lendvay et al., Genetics 144:1399-1412, 1996). Moreover, much of the current understanding of the structure and function of the telomerase complex was derived from yeast studies (Autexier and Lue, Annu Rev Biochem 75:493-517, 2006). In this chapter, we discuss one of the most useful tools for investigating yeast telomerase mechanisms and regulation: the primer extension assay. This assay can be used to examine the overall activity as well as the processivity of telomerase, which represents a unique aspect of telomerase enzymology (Lue et al., Mol Cell Biol 23:8440-8449, 2003; Bosoy and Lue, Nucleic Acids Res 32:93-101, 2004). It can also be employed to analyze the mechanisms of telomerase regulatory proteins (Zappulla et al., Nucleic Acids Res 37:354-367, 2009; DeZwaan and Freeman, Proc Natl Acad Sci USA 106, 17337-17342, 2009).
Collapse
|
29
|
Arora R, Brun CMC, Azzalin CM. TERRA: Long Noncoding RNA at Eukaryotic Telomeres. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2011; 51:65-94. [PMID: 21287134 DOI: 10.1007/978-3-642-16502-3_4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Telomeres protect the ends of linear eukaryotic chromosomes from being recognized as DNA double-stranded breaks, thereby maintaining the stability of our genome. The highly heterochromatic nature of telomeres had, for a long time, reinforced the idea that telomeres were transcriptionally silent. Since a few years, however, we know that DNA-dependent RNA polymerase II transcribes telomeric DNA into TElomeric Repeat-containing RNA (TERRA) molecules in a large variety of eukaryotes. In this chapter, we summarize the current knowledge of telomere structure and function and extensively review data accumulated on TERRA biogenesis and regulation. We also discuss putative functions of TERRA in preserving telomere stability and propose future directions for research encompassing this novel and exciting aspect of telomere biology.
Collapse
Affiliation(s)
- Rajika Arora
- Institute of Biochemistry, ETHZ-Eidgenössische Technische Hochschule Zürich, CH-8093, Zürich, Switzerland
| | | | | |
Collapse
|
30
|
Abstract
In most eukaryotes, telomeric DNA consists of repeats of a short motif that includes consecutive guanines and may hence fold into G-quadruplexes. Budding yeasts have telomeres composed of longer repeats and show variation in the degree of repeat homogeneity. Although telomeric sequences from several organisms have been shown to fold into G-quadruplexes in vitro, surprisingly, no study has been dedicated to the comparison of G-quadruplex folding and stability of known telomeric sequences. Furthermore, to our knowledge, folding of yeast telomeric sequences into intramolecular G-quadruplexes has never been investigated. Using biophysical and biochemical methods, we studied sequences mimicking about four repetitions of telomeric motifs from a variety of organisms, including yeasts, with the aim of comparing the G-quadruplex folding potential of telomeric sequences among eukaryotes. G-quadruplex folding did not appear to be a conserved feature among yeast telomeric sequences. By contrast, all known telomeric sequences from eukaryotes other than yeasts folded into G-quadruplexes. Nevertheless, while G(3)T(1-4)A repeats (found in a variety of organisms) and G(4)T(2,4) repeats (found in ciliates) folded into stable G-quadruplexes, G-quadruplexes formed by repetitions of G(2)T(2)A and G(2)CT(2)A motifs (found in many insects and in nematodes, respectively) appeared to be in equilibrium with non-G-quadruplex structures (likely hairpin-duplexes).
Collapse
Affiliation(s)
- Phong Lan Thao Tran
- INSERM, U565, Acides Nucléiques: Dynamique, Ciblage et Fonctions Biologiques, Muséum National d'Histoire Naturelle, CNRS, UMR7196, Département de Régulations, Développement et Diversité Moléculaire, 43 rue Cuvier, CP26, Paris Cedex 5 -75231, France
| | | | | |
Collapse
|
31
|
Kabir S, Sfeir A, de Lange T. Taking apart Rap1: an adaptor protein with telomeric and non-telomeric functions. Cell Cycle 2010; 9:4061-7. [PMID: 20948311 DOI: 10.4161/cc.9.20.13579] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Mammalian Rap1, a TRF2-interacting protein in the telomeric shelterin complex, was recently shown to repress homology-directed repair at chromosome ends. In addition, Rap1 plays a role in transcriptional regulation and NFκB signaling. Rap1 is unique among the components of shelterin in that it is conserved in budding yeast and has non-telomeric functions. Comparison of mammalian Rap1 to the Rap1 proteins of several budding yeasts and fission yeast reveal both striking similarities and notable differences. The protean nature of Rap1 is best understood by viewing it as an adaptor that can mediate a variety of protein-protein and protein-DNA interactions depending on the organism and the complex in which it is functioning.
Collapse
Affiliation(s)
- Shaheen Kabir
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, NY, USA
| | | | | |
Collapse
|
32
|
Kramara J, Willcox S, Gunisova S, Kinsky S, Nosek J, Griffith JD, Tomaska L. Tay1 protein, a novel telomere binding factor from Yarrowia lipolytica. J Biol Chem 2010; 285:38078-92. [PMID: 20923774 DOI: 10.1074/jbc.m110.127605] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inspection of the complete genome of the yeast Yarrowia lipolytica for the presence of genes encoding homologues of known telomere-binding proteins surprisingly revealed no counterparts of typical yeast Myb domain-containing telomeric factors including Rap1 or Taz1. Instead, we identified a gene, YALIOD10923g, encoding a protein containing two Myb domains, exhibiting a high degree of similarity to the Myb domain of human telomeric proteins TRF1 and TRF2 and homologous to an essential fission yeast protein Mug152 whose expression is elevated during meiosis. The protein, which we named Tay1p (telomere-associated in Yarrowia lipolytica 1), was purified for biochemical studies. Using a model Y. lipolytica telomere, we demonstrate that the protein preferentially binds to Y. lipolytica telomeric tracts. Tay1p binds along the telomeric tract as dimers and larger oligomers, and it is able to remodel the telomeric DNA into both looped structures and synaptic complexes of two model telomere DNAs. The ability of Tay1p to induce dimerization of telomeres in vitro goes in line with its oligomeric nature, where each oligomer can employ several Myb domains to form intermolecular telomere clusters. We also provide experimental evidence that Tay1p may be associated with Y. lipolytica telomeres in vivo. Together with its homologues from Schizosaccharomyces pombe and several basidiomycetous fungi (Sánchez-Alonso, P., and Guzman, P. (2008) Fungal Genet. Biol. 45, S54-S62), Tay1p constitutes a novel family of putative telomeric factors whose analysis may be instrumental in understanding the function and evolution of double-stranded DNA telomeric proteins.
Collapse
Affiliation(s)
- Juraj Kramara
- Department of Genetics, Comenius University, Faculty of Natural Sciences, Mlynska dolina, 842 15 Bratislava, Slovakia
| | | | | | | | | | | | | |
Collapse
|
33
|
Stohr BA, Xu L, Blackburn EH. The terminal telomeric DNA sequence determines the mechanism of dysfunctional telomere fusion. Mol Cell 2010; 39:307-14. [PMID: 20670897 DOI: 10.1016/j.molcel.2010.06.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 02/19/2010] [Accepted: 05/07/2010] [Indexed: 12/27/2022]
Abstract
Mammalian telomeres consist of tandem DNA repeats that bind protective protein factors collectively termed shelterins. Telomere disruption typically results in genome instability induced by telomere fusions. The mechanism of telomere fusion varies depending on the means of telomere disruption. Here, we investigate telomere fusions caused by overexpression of mutant telomerases that add mutated telomeric repeats, thereby compromising shelterin binding to telomeric termini. While all mutant telomeric sequences tested induced heterodicentric chromosome fusions in ATM-competent cells, only those mutant repeat sequences with significant self complementarity induced ATM-independent sister chromatid and isodicentric chromosome fusions. Thus, once a telomere becomes dysfunctional, the terminal telomeric sequence itself determines the fate of that telomere. These results suggest that annealing of self-complementary DNA sequence engages an alternative telomere fusion pathway in human cells, and provide one explanation for the conspicuous lack of self complementarity in the majority of known naturally occurring eukaryotic telomeric sequences.
Collapse
Affiliation(s)
- Bradley A Stohr
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | | |
Collapse
|
34
|
Giraud-Panis MJ, Pisano S, Poulet A, Le Du MH, Gilson E. Structural identity of telomeric complexes. FEBS Lett 2010; 584:3785-99. [PMID: 20696167 DOI: 10.1016/j.febslet.2010.08.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 08/02/2010] [Accepted: 08/02/2010] [Indexed: 02/01/2023]
Abstract
A major issue in telomere research is to understand how the integrity of chromosome ends is controlled. Although several nucleoprotein complexes have been described at the telomeres of different organisms, it is still unclear how they confer a structural identity to chromosome ends in order to mask them from DNA repair and to ensure their proper replication. In this review, we describe how telomeric nucleoprotein complexes are structured, comparing different organisms and trying to link these structures to telomere biology. It emerges that telomeres are formed by a complex and specific network of interactions between DNA, RNA and proteins. The fact that these interactions and associated activities are reinforcing each other might help to guaranty the robustness of telomeric functions across the cell cycle and in the event of cellular perturbations. We propose that telomeric nucleoprotein complexes orient cell fate through dynamic transitions in their structures and their organization.
Collapse
Affiliation(s)
- Marie-Josèphe Giraud-Panis
- University de Nice, Laboratory of Biology and Pathology of Genomes, UMR 6267 CNRS U998 INSERM, Faculté de Médecine, Nice, France
| | | | | | | | | |
Collapse
|
35
|
Kinsky S, Mihalikova A, Kramara J, Nosek J, Tomaska L. Lack of the catalytic subunit of telomerase leads to growth defects accompanied by structural changes at the chromosomal ends in Yarrowia lipolytica. Curr Genet 2010; 56:413-25. [PMID: 20549213 DOI: 10.1007/s00294-010-0310-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 05/26/2010] [Accepted: 05/28/2010] [Indexed: 12/01/2022]
Abstract
Comparative analysis of the telomeres of distantly related species has proven to be helpful for identifying novel components involved in telomere maintenance. We therefore initiated such a study in the nonconventional yeast Yarrowia lipolytica. Its genome encodes only a small fraction of the proteins that are typically associated with telomeres in other yeast models, indicating that its telomeres may employ noncanonical means for their stabilization and maintenance. In this report, we have measured the size of the telomeric fragments in wild-type strains, and characterized the catalytic subunit of telomerase (YlEst2p). In silico analysis of the YlEst2 amino acid sequence revealed the presence of domains typical for telomerase reverse transcriptases. Disruption of YlEST2 is not lethal, but results in retarded growth accompanied by a rapid loss of the telomeric sequences. This phenotype is associated with structural changes at the chromosomal ends in the ΔYlest2 mutants, likely the circularization of all six chromosomes. An apparent absence of several typical telomere-associated factors, as well as the presence of an efficient means of telomerase-independent telomere maintenance, qualify Y. lipolytica as an attractive model for the study of telomere maintenance mechanisms and a promising source of novel players in telomere dynamics.
Collapse
Affiliation(s)
- Slavomir Kinsky
- Department of Genetics, Comenius University, Bratislava, Slovakia
| | | | | | | | | |
Collapse
|
36
|
Telomere maintenance in liquid crystalline chromosomes of dinoflagellates. Chromosoma 2010; 119:485-93. [DOI: 10.1007/s00412-010-0272-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 03/11/2010] [Accepted: 03/11/2010] [Indexed: 10/19/2022]
|
37
|
Abstract
In budding yeast, Cdc13, Stn1, and Ten1 form a heterotrimeric complex (CST) that is essential for telomere protection and maintenance. Previous bioinformatics analysis revealed a putative oligonucleotide/oligosaccharide-binding (OB) fold at the N terminus of Stn1 (Stn1N) that shows limited sequence similarity to the OB fold of Rpa2, a subunit of the eukaryotic ssDNA-binding protein complex replication protein A (RPA). Here we present functional and structural analyses of Stn1 and Ten1 from multiple budding and fission yeast. The crystal structure of the Candida tropicalis Stn1N complexed with Ten1 demonstrates an Rpa2N-Rpa3-like complex. In both structures, the OB folds of the two components pack against each other through interactions between two C-terminal helices. The structure of the C-terminal domain of Saccharomyces cerevisiae Stn1 (Stn1C) was found to comprise two related winged helix-turn-helix (WH) motifs, one of which is most similar to the WH motif at the C terminus of Rpa2, again supporting the notion that Stn1 resembles Rpa2. The crystal structure of the fission yeast Schizosaccharomyces pombe Stn1N-Ten1 complex exhibits a virtually identical architecture as the C. tropicalis Stn1N-Ten1. Functional analyses of the Candida albicans Stn1 and Ten1 proteins revealed critical roles for these proteins in suppressing aberrant telomerase and recombination activities at telomeres. Mutations that disrupt the Stn1-Ten1 interaction induce telomere uncapping and abolish the telomere localization of Ten1. Collectively, our structural and functional studies illustrate that, instead of being confined to budding yeast telomeres, the CST complex may represent an evolutionarily conserved RPA-like telomeric complex at the 3' overhangs that works in parallel with or instead of the well-characterized POT1-TPP1/TEBPalpha-beta complex.
Collapse
|
38
|
Rap1 in Candida albicans: an unusual structural organization and a critical function in suppressing telomere recombination. Mol Cell Biol 2009; 30:1254-68. [PMID: 20008550 DOI: 10.1128/mcb.00986-09] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rap1 (repressor activator protein 1) is a conserved multifunctional protein initially identified as a transcriptional regulator of ribosomal protein genes in Saccharomyces cerevisiae but subsequently shown to play diverse functions at multiple chromosomal loci, including telomeres. The function of Rap1 appears to be evolutionarily plastic, especially in the budding yeast lineages. We report here our biochemical and molecular genetic characterizations of Candida albicans Rap1, which exhibits an unusual, miniaturized domain organization in comparison to the S. cerevisiae homologue. We show that in contrast to S. cerevisiae, C. albicans RAP1 is not essential for cell viability but is critical for maintaining normal telomere length and structure. The rap1 null mutant exhibits drastic telomere-length dysregulation and accumulates high levels of telomere circles, which can be largely attributed to aberrant recombination activities at telomeres. Analysis of combination mutants indicates that Rap1 and other telomere proteins mediate overlapping but nonredundant roles in telomere protection. Consistent with the telomere phenotypes of the mutant, C. albicans Rap1 is localized to telomeres in vivo and recognizes the unusual telomere repeat unit with high affinity and sequence specificity in vitro. The DNA-binding Myb domain of C. albicans Rap1 is sufficient to suppress most of the telomere aberrations observed in the null mutant. Notably, we were unable to detect specific binding of C. albicans Rap1 to gene promoters in vivo or in vitro, suggesting that its functions are more circumscribed in this organism. Our findings provide insights on the evolution and mechanistic plasticity of a widely conserved and functionally critical telomere component.
Collapse
|
39
|
Bombarová M, Vítková M, Špakulová M, Koubková B. Telomere analysis of platyhelminths and acanthocephalans by FISH and Southern hybridization. Genome 2009; 52:897-903. [DOI: 10.1139/g09-063] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the composition of telomeres in chromosomes of parasitic worms, representatives of the flatworm groups Monogenea and Cestoda (Platyhelminthes), and thorny-headed worms (Syndermata: Acanthocephala) by fluorescence in situ hybridization (FISH) with different telomeric repeat probes. Our results show that the (TTAGGG)n sequence, supposed to be the ancestral telomeric repeat motif of Metazoa, is conserved in Monogenea ( Paradiplozoon homoion ) and Cestoda ( Caryophyllaeus laticeps , Caryophyllaeides fennica , and Nippotaenia mogurndae ) but not in Acanthocephala ( Pomphorhynchus laevis and Pomphorhynchus tereticollis ). In the Pomphorhynchus species, no hybridization signals were obtained with the “nematode” (TTAGGC)n, “arthropod” (TTAGG)n, and bdelloid (TGTGGG)n telomeric probes using FISH with their chromosomes and Southern hybridization with P. laevis DNA. Therefore, we suggest that parasitic Acanthocephala have evolved yet unknown telomeric repeat motifs or different mechanisms of telomere maintenance.
Collapse
Affiliation(s)
- Marta Bombarová
- Parasitological Institute, Slovak Academy of Sciences, Hlinkova 3, 04001 Košice, Slovakia
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Biology Centre of the Academy of Sciences of the Czech Republic (BC ASCR), Institute of Entomology, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Magda Vítková
- Parasitological Institute, Slovak Academy of Sciences, Hlinkova 3, 04001 Košice, Slovakia
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Biology Centre of the Academy of Sciences of the Czech Republic (BC ASCR), Institute of Entomology, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Marta Špakulová
- Parasitological Institute, Slovak Academy of Sciences, Hlinkova 3, 04001 Košice, Slovakia
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Biology Centre of the Academy of Sciences of the Czech Republic (BC ASCR), Institute of Entomology, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Božena Koubková
- Parasitological Institute, Slovak Academy of Sciences, Hlinkova 3, 04001 Košice, Slovakia
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Biology Centre of the Academy of Sciences of the Czech Republic (BC ASCR), Institute of Entomology, Branišovská 31, 370 05 České Budějovice, Czech Republic
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| |
Collapse
|
40
|
Lue NF. Plasticity of telomere maintenance mechanisms in yeast. Trends Biochem Sci 2009; 35:8-17. [PMID: 19846312 DOI: 10.1016/j.tibs.2009.08.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2009] [Revised: 08/25/2009] [Accepted: 08/27/2009] [Indexed: 01/04/2023]
Abstract
Telomeres, the nucleoprotein structures located at linear eukaryotic chromosomal termini, are essential for chromosome stability and are maintained by the special reverse transcriptase named telomerase. In the Saccharomycotina subphylum of budding yeast, telomere repeat sequences and binding factors, as well as telomerase components, are exceptionally diverse and distinct from those found in other eukaryotes. In this survey, I report a comparative analysis of the domain structures of telomere and telomerase-related factors made possible by the recent sequencing of multiple yeast genomes. This analysis revealed both conserved and variable aspects of telomere maintenance. Based on these findings, I propose a plausible series of evolutionary events in budding yeast to account for its exceptional telomere structural divergence.
Collapse
Affiliation(s)
- Neal F Lue
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY 10065, USA.
| |
Collapse
|
41
|
Yang X, Figueiredo LM, Espinal A, Okubo E, Li B. RAP1 is essential for silencing telomeric variant surface glycoprotein genes in Trypanosoma brucei. Cell 2009; 137:99-109. [PMID: 19345190 DOI: 10.1016/j.cell.2009.01.037] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 10/10/2008] [Accepted: 01/14/2009] [Indexed: 01/08/2023]
Abstract
Trypanosoma brucei expresses variant surface glycoprotein (VSG) genes in a strictly monoallelic fashion in its mammalian hosts, but it is unclear how this important virulence mechanism is enforced. Telomere position effect, an epigenetic phenomenon, has been proposed to play a critical role in VSG regulation, yet no telomeric protein has been identified whose disruption led to VSG derepression. We now identify tbRAP1 as an intrinsic component of the T. brucei telomere complex and a major regulator for silencing VSG expression sites (ESs). Knockdown of tbRAP1 led to derepression of all VSGs in silent ESs, but not VSGs located elsewhere, and resulted in stronger derepression of genes located within 10 kb from telomeres than genes located further upstream. This graduated silencing pattern suggests that telomere integrity plays a key role in tbRAP1-dependent silencing and VSG regulation.
Collapse
Affiliation(s)
- Xiaofeng Yang
- Department of Biological, Geological, and Environmental Sciences, Center for Gene Regulation in Health and Diseases, Cleveland State University, Cleveland, OH 44115, USA
| | | | | | | | | |
Collapse
|
42
|
De Cian A, Grellier P, Mouray E, Depoix D, Bertrand H, Monchaud D, Teulade-Fichou MP, Mergny JL, Alberti P. Plasmodium telomeric sequences: structure, stability and quadruplex targeting by small compounds. Chembiochem 2009; 9:2730-9. [PMID: 18924216 DOI: 10.1002/cbic.200800330] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The increasing resistance of Plasmodium falciparum to the most commonly used antimalarial drugs makes it necessary to identify new therapeutic targets. The telomeres of the parasite could constitute an attractive target. They are composed of repetitions of a degenerate motif ((5')GGGTTYA(3'), where Y is T or C), different from the human one ((5')GGGTTA(3')). In this report we investigate the possibility of targeting Plasmodium telomeres with G-quadruplex ligands. Through solution hybridisation assays we provide evidence of the existence of a telomeric 3' G-overhang in P. falciparum genomic DNA. Through UV spectroscopy studies we demonstrate that stable G-quadruplex structures are formed at physiological temperature by sequences composed of the degenerate Plasmodium telomeric motif. Through a FRET melting assay we show stabilisation of Plasmodium telomeric G-quadruplexes by a variety of ligands. Many of the tested ligands display strong quadruplex versus duplex selectivity, but show little discrimination between human and Plasmodium telomeric quadruplexes.
Collapse
|
43
|
Benbow SZ, DuBois ML. The dosage of chromatin proteins affects transcriptional silencing and DNA repair in Saccharomyces cerevisiae. FEBS Lett 2008; 582:497-502. [PMID: 18211810 DOI: 10.1016/j.febslet.2008.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Revised: 01/08/2008] [Accepted: 01/12/2008] [Indexed: 11/24/2022]
Abstract
Alterations in protein composition or dosage within chromatin may trigger changes in processes such as gene expression and DNA repair. Through transposon mutagenesis and targeted gene deletions in haploids and diploids of Saccharomyces cerevisiae, we identified mutations that affect telomeric silencing in genes encoding telomere-associated Sir4p and Yku80p and chromatin remodeling ATPases Ies2p and Rsc1p. We found that sir4/SIR4 heterozygous diploids efficiently silence the mating type locus HMR but not telomeres, and diploids heterozygous for yku80 and ies2 mutations are inefficient at DNA repair. In contrast, strains heterozygous for most chromatin remodeling ATPase mutations retain wild-type silencing and DNA repair levels. Thus, in diploids, chromatin structures required for DNA repair and telomeric silencing are sensitive to dosage changes.
Collapse
Affiliation(s)
- Sarah Z Benbow
- Seattle University, Department of Biology, 901 12th Avenue, Seattle, WA 98122, USA
| | | |
Collapse
|
44
|
Abstract
The replication of the ends of linear chromosomes, or telomeres, poses unique problems, which must be solved to maintain genome integrity and to allow cell division to occur. Here, we describe and compare the timing and specific mechanisms that are required to initiate, control and coordinate synthesis of the leading and lagging strands at telomeres in yeasts, ciliates and mammals. Overall, it emerges that telomere replication relies on a strong synergy between the conventional replication machinery, telomere protection systems, DNA-damage-response pathways and chromosomal organization.
Collapse
Affiliation(s)
- Eric Gilson
- Laboratoire de Biologie Moléculaire et Cellulaire, UMR5239, IFR 128, Centre National de la Recherche Scientifique, University Lyon 1, Faculty of Medicine Lyon-Sud, Hospices Civils de Lyon, Ecole Normale Supérieure de Lyon,France.
| | | |
Collapse
|
45
|
Ottaviani A, Gilson E, Magdinier F. Telomeric position effect: from the yeast paradigm to human pathologies? Biochimie 2007; 90:93-107. [PMID: 17868970 DOI: 10.1016/j.biochi.2007.07.022] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 07/25/2007] [Indexed: 01/28/2023]
Abstract
Alteration of the epigenome is associated with a wide range of human diseases. Therefore, deciphering the pathways that regulate the epigenetic modulation of gene expression is a major milestone for the understanding of diverse biological mechanisms and subsequently human pathologies. Although often evoked, little is known on the implication of telomeric position effect, a silencing mechanism combining telomere architecture and classical heterochromatin features, in human cells. Nevertheless, this particular silencing mechanism has been investigated in different organisms and several ingredients are likely conserved during evolution. Subtelomeres are highly dynamic regions near the end of the chromosomes that are prone to recombination and may buffer or facilitate the spreading of silencing that emanates from the telomere. Therefore, the composition and integrity of these regions also concur to the propensity of telomeres to regulate the expression, replication and recombination of adjacent regions. Here we describe the similarities and disparities that exist among the different species at chromosome ends with regard to telomeric silencing regulation with a special accent on its implication in numerous human pathologies.
Collapse
Affiliation(s)
- Alexandre Ottaviani
- Laboratoire de Biologie Moléculaire de la Cellule, CNRS UMR5239, Ecole Normale Supérieure de Lyon, UCBL1, IFR128, 46 allée d'Italie, 69364 Lyon Cedex 07, France
| | | | | |
Collapse
|
46
|
Traut W, Szczepanowski M, Vítková M, Opitz C, Marec F, Zrzavý J. The telomere repeat motif of basal Metazoa. Chromosome Res 2007; 15:371-82. [PMID: 17385051 DOI: 10.1007/s10577-007-1132-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2007] [Revised: 02/13/2007] [Accepted: 02/13/2007] [Indexed: 11/29/2022]
Abstract
In most eukaryotes the telomeres consist of short DNA tandem repeats and associated proteins. Telomeric repeats are added to the chromosome ends by telomerase, a specialized reverse transcriptase. We examined telomerase activity and telomere repeat sequences in representatives of basal metazoan groups. Our results show that the 'vertebrate' telomere motif (TTAGGG)( n ) is present in all basal metazoan groups, i.e. sponges, Cnidaria, Ctenophora, and Placozoa, and also in the unicellular metazoan sister group, the Choanozoa. Thus it can be considered the ancestral telomere repeat motif of Metazoa. It has been conserved from the metazoan radiation in most animal phylogenetic lineages, and replaced by other motifs-according to our present knowledge-only in two major lineages, Arthropoda and Nematoda.
Collapse
Affiliation(s)
- Walther Traut
- Institut für Biologie, Zentrum für Medizinische Struktur- und Zellbiologie, Universität zu Lübeck, D-23538, Lübeck, Germany.
| | | | | | | | | | | |
Collapse
|
47
|
Berthiau AS, Yankulov K, Bah A, Revardel E, Luciano P, Wellinger RJ, Géli V, Gilson E. Subtelomeric proteins negatively regulate telomere elongation in budding yeast. EMBO J 2006; 25:846-56. [PMID: 16467854 PMCID: PMC1383556 DOI: 10.1038/sj.emboj.7600975] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Accepted: 01/09/2006] [Indexed: 11/09/2022] Open
Abstract
The Tbf1 and Reb1 proteins are present in yeast subtelomeric regions. We establish in this work that they inhibit telomerase-dependent lengthening of telomere. For example, tethering the N-terminal domain of Tbf1 and Reb1 in a subtelomeric region shortens that telomere proportionally to the number of domains bound. We further identified a 90 amino-acid long sequence within the N-terminal domain of Tbf1 that is necessary but not sufficient for its length regulation properties. The role of the subtelomeric factors in telomere length regulation is antagonized by TEL1 and does not correlate with a global telomere derepression. We show that the absence of TEL1 induces an alteration in the structure of telomeric chromatin, as defined biochemically by an increased susceptibility to nucleases and a greater heterogeneity of products. We propose that the absence of TEL1 modifies the organization of the telomeres, which allows Tbf1 and Reb1 to cis-inhibit telomerase. The involvement of subtelomeric factors in telomere length regulation provides a possible mechanism for the chromosome-specific length setting observed at yeast and human telomeres.
Collapse
Affiliation(s)
- Anne-Sophie Berthiau
- Laboratoire de Biologie Moléculaire de la Cellule de l'Ecole Normale Supérieure de Lyon, CNRS UMR5161, IFR 128, Lyon, France
| | - Krassimir Yankulov
- Laboratoire de Biologie Moléculaire de la Cellule de l'Ecole Normale Supérieure de Lyon, CNRS UMR5161, IFR 128, Lyon, France
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Amadou Bah
- Laboratoire de Biologie Moléculaire de la Cellule de l'Ecole Normale Supérieure de Lyon, CNRS UMR5161, IFR 128, Lyon, France
- Department of Microbiology and Infectious Diseases, Faculty of Medicine, Universite de Sherbrooke 3001, Sherbrooke, Quebec, Canada
| | - Emmanuelle Revardel
- Laboratoire de Biologie Moléculaire de la Cellule de l'Ecole Normale Supérieure de Lyon, CNRS UMR5161, IFR 128, Lyon, France
| | - Pierre Luciano
- Laboratoire d'Instabilité Génétique et Cancérogenèse (IGC), CNRS, Marseille, France
| | - Raymund J Wellinger
- Department of Microbiology and Infectious Diseases, Faculty of Medicine, Universite de Sherbrooke 3001, Sherbrooke, Quebec, Canada
| | - Vincent Géli
- Laboratoire d'Instabilité Génétique et Cancérogenèse (IGC), CNRS, Marseille, France
| | - Eric Gilson
- Laboratoire de Biologie Moléculaire de la Cellule de l'Ecole Normale Supérieure de Lyon, CNRS UMR5161, IFR 128, Lyon, France
- Laboratoire de Biologie Moléculaire et Cellulaire, Ecole Normale Supérieure, UMR5161 CNRS/ENSL, 46 Allee d'italie, 69364 Lyon Cedex 07, France. Tel.: +33 472 728 453; Fax: +33 472 728 686; E-mail:
| |
Collapse
|
48
|
Current awareness on yeast. Yeast 2006. [DOI: 10.1002/yea.1285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
|