scholarly journals Biallelic variants in YRDC cause a developmental disorder with progeroid features

2021 ◽  
Author(s):  
Julia Schmidt ◽  
Jonas Goergens ◽  
Tatiana Pochechueva ◽  
Annika Kotter ◽  
Niko Schwenzer ◽  
...  
Keyword(s):  
Developmental Disorder ◽  
Functional Characterization ◽  
Subcutaneous Fat ◽  
Dermal Fibroblasts ◽  
Telomere Maintenance ◽  
Fish Analysis ◽  
Sequencing Analysis ◽  
Telomere Shortening ◽  
The Impact ◽  
Keops Complex

AbstractThe highly conserved YrdC domain-containing protein (YRDC) interacts with the well-described KEOPS complex, regulating specific tRNA modifications to ensure accurate protein synthesis. Previous studies have linked the KEOPS complex to a role in promoting telomere maintenance and controlling genome integrity. Here, we report on a newborn with a severe neonatal progeroid phenotype including generalized loss of subcutaneous fat, microcephaly, growth retardation, wrinkled skin, renal failure, and premature death at the age of 12 days. By trio whole-exome sequencing, we identified a novel homozygous missense mutation, c.662T > C, in YRDC affecting an evolutionary highly conserved amino acid (p.Ile221Thr). Functional characterization of patient-derived dermal fibroblasts revealed that this mutation impairs YRDC function and consequently results in reduced t6A modifications of tRNAs. Furthermore, we established and performed a novel and highly sensitive 3-D Q-FISH analysis based on single-telomere detection to investigate the impact of YRDC on telomere maintenance. This analysis revealed significant telomere shortening in YRDC-mutant cells. Moreover, single-cell RNA sequencing analysis of YRDC-mutant fibroblasts revealed significant transcriptome-wide changes in gene expression, specifically enriched for genes associated with processes involved in DNA repair. We next examined the DNA damage response of patient’s dermal fibroblasts and detected an increased susceptibility to genotoxic agents and a global DNA double-strand break repair defect. Thus, our data suggest that YRDC may affect the maintenance of genomic stability. Together, our findings indicate that biallelic variants in YRDC result in a developmental disorder with progeroid features and might be linked to increased genomic instability and telomere shortening.

Unbalanced X Chromosome Inactivation Independent of Telomere Shortening in Mice Heterozygous for a Mutant Dyskerin Allele.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 184-184
Author(s):  
Baiwei Gu ◽  
Jun He ◽  
Monica Bessler ◽  
Philip J. Mason
Keyword(s):  
Bone Marrow ◽  
Ribosome Biogenesis ◽  
Es Cells ◽  
X Inactivation ◽  
Telomere Maintenance ◽  
Male Mice ◽  
Wild Type ◽  
Telomere Shortening ◽  
Ribonucleoprotein Complexes ◽  
The Impact

Abstract X-linked Dyskeratosis Congenita (DC) is a rare recessive disorder caused by mutations in the DKC1 gene that encodes dyskerin. Dyskerin is part of ribonucleoprotein complexes that participate in two different pathways: ribosome biogenesis and telomere maintenance. It is the subject of intense debate whether disease manifestations in DC are due to dysfunctional telomere maintenances or are caused by a defect in ribosome biogenesis. Pathogenic mutations in dyskerin cause telomere shortening and patients with X-linked DC have critically short telomeres, However, whether there is an additional defect in ribosome biogenesis is difficult to investigate. To dissect the impact of a pathogenic dyskerin mutation on telomeres from the possible additional impact on ribosome biogenesis in an in vivo model, we generated mice expressing a mutant dyskerin protein. Because laboratory mice have very long telomeres a short telomere phenotype requires several generations of inbreeding, whereas a phenotype seen in the first generation is likely to be caused by the defect in ribosome biogenesis. To delete the last 21 amino acids of dyskerin (Del15) we used homologous recombination followed by conditional gene deletion in murine embryonic stem (ES) cells and in mice. Six independent ES cell clones with the deleted Dkc1 gene were obtained. In vitro analysis of the ES cells showed that the Del15 mutation led to dramatically decreased expression of a truncated dyskerin protein with decreased accumulation of the telomerase RNA. In addition, both reduction in telomerase activity and significant telomere shortening after 65 passages were observed. These findings indicate that the Del15 mutation impairs the telomerase maintenance pathway. After testing the accumulation of a series of mouse H/ACA snoRNA in Del15 ES cells, we found a decrease of the mU68 and mE1 snoRNAs suggesting the mutation may also confer effects which are outside the telomerase pathway. We therefore went on to produce a line of mice expressing the truncated Dkc1 protein and were able to obtain male mice hemizygous for the mutant Dkc1 gene as well as female heterozgotes. The male mice express the truncated dyskerin protein and show no gross abnormality up to 6 months of age. Interestingly, heterozygous female mice were healthy as well but the truncated dyskerin protein was dramatically decreased in expression compared to the wild type dyskerin in spleen, thymus, and bone marrow, but not in liver and brain. This result must derive from preferential proliferation of cells expressing wild type dyskerin after random X-inactivation in early embryogenesis. Our analysis indicates that the mutant dyskerin impairs the proliferation in hematopoietic tissues while it does not affect cells which are not rapidly proliferating such as those in liver and brain. Because of the early appearance of the skewed X-inactivation phenotype we conclude that skewing in these mice is caused by a telomere independent mechanism. Interestingly, the lack of overt DC-like abnormalities in the male hemizygous mice indicates that this proliferative disadvantage is insufficient to cause bone marrow failure but in combination with impaired telomere maintenance may accelerate the onset and severity of disease and thus explain the earlier and more severe manifestation in X-linked DC compared to autosomal dominant DC which only affects the telomerase pathway.

Regulation And Effect Of Telomerase And Telomeric Length In Stem Cells

2020 ◽  
Vol 15 ◽  
Author(s):  
Basak Celtikci ◽  
Gulnihal Kulaksiz Erkmen ◽  
Zeliha Gunnur Dikmen
Keyword(s):  
Telomere Length ◽  
Somatic Cells ◽  
Telomere Maintenance ◽  
The Other ◽  
Telomerase Reverse Transcriptase ◽  
Human Telomerase Reverse Transcriptase ◽  
Telomere Shortening ◽  
Maintenance Mechanism ◽  
Associated Diseases ◽  
Human Telomerase

: Telomeres are the protective end caps of eukaryotic chromosomes and they decide the proliferative lifespan of somatic cells, as the guardians of the cell replication. Telomere length in leucocytes reflects telomere length in other somatic cells. Leucocyte telomere length can be a biomarker of human ageing. The risk of diseases, which are associated with reduced cell proliferation and tissue degeneration, including aging or aging-associated diseases, such as dyskeratosis congenita, cardiovascular diseases, pulmonary fibrosis and aplastic anemia, are correlated with an increase in short telomeres. On the other hand, the risk of diseases, which are associated with increased proliferative growth, including major cancers, is correlated with long telomeres. In most of the cancers, a telomere maintenance mechanism during DNA replication is essential. The reactivation of the functional ribonucleoprotein holoenzyme complex [telomerase] starts the cascade from normal and premalignant somatic cells to advanced malignant cells. Telomerase is overexpressed during the development of cancer and embryonic stem cells, through controlling genome integrity, cancer formation and stemness. Cancer cells have mechanisms to maintain telomeres to avoid initiation of cellular senescence or apoptosis, and halting cell division by critically short telomeres. Modulation of the human telomerase reverse transcriptase is the ratelimiting step for the production of functional telomerase and the telomere maintenance. Human telomerase reverse transcriptase promoter promotes its gene expression only in tumor cells, but not in normal cells. Some cancers activate an alternative lengthening of telomeres maintenance mechanism via DNA recombination to unshorten their telomeres. Not only heritability but also oxidative stress, inflammation, environmental factors, and therapeutic interventions have an effect on telomere shortening, explaining the variability in telomere length across individuals. There have been a large number of publications, which correlate human diseases with progressive telomere shortening. Telomere length of an individual at birth is also important to follow up telomere shortening, and it can be used as biomarkers for healthy aging. On the other hand, understanding of cellular stress factors, which affect stem cell behavior, will be useful in regeneration or treatment in cancer and age-associated diseases. In this review, we will understand the connection between stem cell and telomere biology, cancer, and aging-associated diseases. This connection may be useful for discovering novel drug targets and improve outcomes for patients having cancer and aging-associated diseases.

scholarly journals Metagenomic Analysis of the Fecal Archaeome in Suckling Piglets Following Perinatal Tulathromycin Metaphylaxis

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1825
Author(s):  
Mohamed Zeineldin ◽  
Ameer Megahed ◽  
Benjamin Blair ◽  
Brian Aldridge ◽  
James Lowe
Keyword(s):  
Sequencing Analysis ◽  
Metagenomic Sequencing ◽  
Post Intervention ◽  
Gastrointestinal Microbiome ◽  
Health And Wellbeing ◽  
Suckling Piglets ◽  
And Function ◽  
Changes Over Time ◽  
And Control ◽  
The Impact

The gastrointestinal microbiome plays an important role in swine health and wellbeing, but the gut archaeome structure and function in swine remain largely unexplored. To date, no metagenomics-based analysis has been done to assess the impact of an early life antimicrobials intervention on the gut archaeome. The aim of this study was to investigate the effects of perinatal tulathromycin (TUL) administration on the fecal archaeome composition and diversity in suckling piglets using metagenomic sequencing analysis. Sixteen litters were administered one of two treatments (TUL; 2.5 mg/kg IM and control (CONT); saline 1cc IM) soon after birth. Deep fecal swabs were collected from all piglets on days 0 (prior to treatment), 5, and 20 post intervention. Each piglet’s fecal archaeome was composed of rich and diverse communities that showed significant changes over time during the suckling period. At the phylum level, 98.24% of the fecal archaeome across all samples belonged to Euryarchaeota. At the genus level, the predominant archaeal genera across all samples were Methanobrevibacter (43.31%), Methanosarcina (10.84%), Methanococcus (6.51%), and Methanocorpusculum (6.01%). The composition and diversity of the fecal archaeome between the TUL and CONT groups at the same time points were statistically insignificant. Our findings indicate that perinatal TUL metaphylaxis seems to have a minimal effect on the gut archaeome composition and diversity in sucking piglets. This study improves our current understanding of the fecal archaeome structure in sucking piglets and provides a rationale for future studies to decipher its role in and impact on host robustness during this critical phase of production.

scholarly journals Mixed Neuroendocrine/Non-neuroendocrine Neoplasm (MiNEN) of the Ovary Arising from Endometriosis: Molecular Pathology Analysis in Support of a Pathogenetic Paradigm

2021 ◽  
Author(s):  
Roberta Maragliano ◽  
Laura Libera ◽  
Ileana Carnevali ◽  
Valeria Pensotti ◽  
Giovanna De Vecchi ◽  
...  
Keyword(s):  
Large Cell ◽  
Neuroendocrine Neoplasm ◽  
Molecular Profile ◽  
Neuroendocrine Neoplasms ◽  
Fish Analysis ◽  
Sequencing Analysis ◽  
Endometrioid Carcinoma ◽  
Preneoplastic Lesions ◽  
Ovarian Endometriosis ◽  
Neuroendocrine Carcinomas

AbstractPrimary ovarian neuroendocrine neoplasms (Ov-NENs) are infrequent and mainly represented by well-differentiated forms (neuroendocrine tumors — NETs — or carcinoids). Poorly differentiated neuroendocrine carcinomas (Ov-NECs) are exceedingly rare and only few cases have been reported in the literature. A subset of Ov-NECs are admixed with non-neuroendocrine carcinomas, as it occurs in other female genital organs, as well (mostly endometrium and uterine cervix), and may be assimilated to mixed neuroendocrine/non-neuroendocrine neoplasms (MiNENs) described in digestive and extra-digestive sites. Here, we present a case of large cell Ov-NEC admixed with an endometrioid carcinoma of the ovary, arising in the context of ovarian endometriosis, associated with a uterine endometrial atypical hyperplasia (EAH). We performed targeted next-generation sequencing analysis, along with a comprehensive immunohistochemical study and FISH analysis for TP53 locus, separately on the four morphologically distinct lesions (Ov-NEC, endometrioid carcinoma, endometriosis, and EAH). The results of our study identified molecular alterations of cancer-related genes (PIK3CA, CTNNB1, TP53, RB1, ARID1A, and p16), which were present with an increasing gradient from preneoplastic lesions to malignant proliferations, both neuroendocrine and non-neuroendocrine components. In conclusion, our findings underscored that the two neoplastic components of this Ov-MiNEN share a substantially identical molecular profile and they progress from a preexisting ovarian endometriotic lesion, in a patient with a coexisting preneoplastic proliferation of the endometrium, genotypically and phenotypically related to the ovarian neoplasm. Moreover, this study supports the inclusion of MiNEN in the spectrum ovarian and, possibly, of all gynecological NENs, among which they are currently not classified.

scholarly journals Inhibition of p38 Mitogen-Activated Protein Kinase Impairs Mayaro Virus Replication in Human Dermal Fibroblasts and HeLa Cells

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1156
Author(s):  
Madelaine Sugasti-Salazar ◽  
Yessica Y. Llamas-González ◽  
Dalkiria Campos ◽  
José González-Santamaría
Keyword(s):  
Protein Expression ◽  
Hela Cells ◽  
Plaque Assay ◽  
Dermal Fibroblasts ◽  
Dependent Manner ◽  
Human Dermal Fibroblasts ◽  
Mitogen Activated Protein ◽  
Mayaro Virus ◽  
The Impact ◽  
Dose Dependent

Mayaro virus (MAYV) hijacks the host’s cell machinery to effectively replicate. The mitogen-activated protein kinases (MAPKs) p38, JNK, and ERK1/2 have emerged as crucial cellular factors implicated in different stages of the viral cycle. However, whether MAYV uses these MAPKs to competently replicate has not yet been determined. The aim of this study was to evaluate the impact of MAPK inhibition on MAYV replication using primary human dermal fibroblasts (HDFs) and HeLa cells. Viral yields in supernatants from MAYV-infected cells treated or untreated with inhibitors SB203580, SP600125, U0126, or Losmapimod were quantified using plaque assay. Additionally, viral protein expression was analyzed using immunoblot and immunofluorescence. Knockdown of p38⍺/p38β isoforms was performed in HDFs using the PROTACs molecule NR-7h. Our data demonstrated that HDFs are highly susceptible to MAYV infection. SB203580, a p38 inhibitor, reduced MAYV replication in a dose-dependent manner in both HDFs and HeLa cells. Additionally, SB203580 significantly decreased viral E1 protein expression. Similarly, knockdown or inhibition of p38⍺/p38β isoforms with NR-7h or Losmapimod, respectively, affected MAYV replication in a dose-dependent manner. Collectively, these findings suggest that p38 could play an important role in MAYV replication and could serve as a therapeutic target to control MAYV infection.

scholarly journals POS0352 ALLELIC VARIANTS IN THE ABCG2 GENE CAN LEAD TO HYPERURICEMIA AND GOUT

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 406.2-407
Author(s):  
K. Pavelcova ◽  
J. Bohata ◽  
B. Stiburkova
Keyword(s):  
Uric Acid ◽  
Rare Variants ◽  
Stop Codon ◽  
Functional Characterization ◽  
Premature Stop Codon ◽  
European Population ◽  
Allelic Variants ◽  
Abcg2 Protein ◽  
The Impact ◽  
Abcg2 Gene

Background:The level of uric acid is largely determined by the functions of urate transporters, which are located in the kidney and intestine. The ABCG2 protein is the major excretor of uric acid and its dysfunction may lead to the development of hyperuricemia and gout.Objectives:The aim of our study was to detect the occurrence and frequency of allelic variants in the ABCG2 gene that can lead to impaired function of the ABCG2 protein and to the development of hyperuricemia and gout.Methods:We examined allelic variants of ABCG2 using PCR amplification and Sanger sequencing of all coding regions and exon-intron boundaries in 359 patients with primary hyperuricemia and gout.Results:We found a rare in-frame deletion p.K360del and 15 missense variants, two of which were common (p.V12M, p.Q141K) and 13 were very rare (p.M71V, p.G74D, p.M131I, p.R147W, p.T153M, p.I242T, p.R236X, p.F373C, p.T421A, p.T434M, p.S476P, p.S572R, p.D620N). The p.R236X variant leads to a premature stop codon. The p.V12M variant probably has a protective effect against gout (minor allele frequency – MAF – in our cohort = 0,025 / MAF in the European population = 0,061), while the p.Q141K variant increases the risk of gout (MAF in our cohort = 0,213 / MAF in the European population = 0,094) (1). As for the rare variants, the p.R147W, p.T153M, p.F373C, p.T434M, p.S476P and p.S572R according to functional analyzes reduce the function of the ABCG2 protein (2). Based on in silico prediction, the impact on reduced function is expected for variants p.M71V, p.G74D, p.M131I, p.R147W, p.I242T, p.F373C, p.T434M, p.S476P and p.S572R.Conclusion:Our data suggest that the common variant p.Q141K and most of the rare variants in the ABCG2 gene affect the function of the ABCG2 urate transporter and are a genetic risk factor for hyperuricemia and gout.References:[1]Stiburkova B, et al. Functional non-synonymous variants of ABCG2 and gout risk. Rheumatology (Oxford). 2017 Nov 1; 56(11):1982-1992.[2]Toyoda Y, et al. Functional characterization of clinically-relevant rare variants in ABCG2 identified in a gout and hyperuricemia cohort. Cells. 2019 Apr 18;8(4).Acknowledgements:This study was supported by the project for conceptual development of research organization 00023728 (Institute of Rheumatology) and RVO VFN64165.Disclosure of Interests:None declared

scholarly journals Structural genomics approach to investigate deleterious impact of nsSNPs in conserved telomere maintenance component 1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arunabh Choudhury ◽  
Taj Mohammad ◽  
Nikhil Samarth ◽  
Afzal Hussain ◽  
Md. Tabish Rehman ◽  
...  
Keyword(s):  
Noncovalent Interactions ◽  
Md Simulations ◽  
Telomere Maintenance ◽  
Nucleotide Polymorphisms ◽  
Telomeric Dna ◽  
Congenital Diseases ◽  
Ob Fold ◽  
Significant Conformational Change ◽  
The Stability ◽  
The Impact

AbstractConserved telomere maintenance component 1 (CTC1) is an important component of the CST (CTC1-STN1-TEN1) complex, involved in maintaining the stability of telomeric DNA. Several non-synonymous single-nucleotide polymorphisms (nsSNPs) in CTC1 have been reported to cause Coats plus syndrome and Dyskeratosis congenital diseases. Here, we have performed sequence and structure analyses of nsSNPs of CTC1 using state-of-the-art computational methods. The structure-based study focuses on the C-terminal OB-fold region of CTC1. There are 11 pathogenic mutations identified, and detailed structural analyses were performed. These mutations cause a significant disruption of noncovalent interactions, which may be a possible reason for CTC1 instability and consequent diseases. To see the impact of such mutations on the protein conformation, all-atom molecular dynamics (MD) simulations of CTC1-wild-type (WT) and two of the selected mutations, R806C and R806L for 200 ns, were carried out. A significant conformational change in the structure of the R806C mutant was observed. This study provides a valuable direction to understand the molecular basis of CTC1 dysfunction in disease progression, including Coats plus syndrome.

scholarly journals Expansion of the fatty acyl reductase gene family shaped pheromone communication in Hymenoptera

2018 ◽  
Author(s):  
Michal Tupec ◽  
Aleš Buček ◽  
Heiko Vogel ◽  
Václav Janoušek ◽  
Darina Prchalová ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Gene Family ◽  
Fat Body ◽  
Functional Characterization ◽  
Acid Methyl Ester ◽  
Fatty Acyl ◽  
Sequencing Analysis ◽  
Pheromone Communication ◽  
Marking Pheromone ◽  
Fatty Acyl Reductase

AbstractThe conserved fatty acyl reductase (FAR) family is involved in biosynthesis of fatty alcohols that serve a range of biological roles. In moths, butterflies (Lepidoptera), and bees (Hymenoptera), FARs biosynthesize fatty alcohol pheromones participating in mate-finding strategies. Using a combination of next-generation sequencing, analysis of transposable elements (TE) in the genomic environment of FAR genes, and functional characterization of FARs from Bombus lucorum, B. lapidarius, and B. terrestris, we uncovered a massive expansion of the FAR gene family in Hymenoptera, presumably facilitated by TEs. Expansion occurred in the common ancestor of bumblebees (Bombini) and stingless bees (Meliponini) after their divergence from the honeybee lineage. We found that FARs from the expanded FAR-A orthology group contributed to the species-specific male marking pheromone composition. Our results indicate that TE-mediated expansion and functional diversification of the FAR gene family played a key role in the evolution of pheromone communication in the crown group of Hymenoptera.AbbreviationsMMP: male marking pheromone, FA: fatty acid, FAME: fatty acid methyl ester, FAR: fatty acyl reductase, LG: labial gland, FB: fat body, TE: transposable element.

scholarly journals Identification of Regulatory circRNAs Involved in the Pathogenesis of Acute Myocardial Infarction

2021 ◽  
Vol 11 ◽  
Author(s):  
Cuimei Zhao ◽  
Jingjing Liu ◽  
Wen Ge ◽  
Zhi Li ◽  
Mengwei Lv ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Coronary Arteries ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Differential Expression Analysis ◽  
Functional Characterization ◽  
High Morbidity ◽  
The Impact ◽  
Runx1 Expression

BackgroundAcute myocardial infarction (AMI) has high morbidity and mortality worldwide. However, the pathogenesis of AMI is still unclear, and the impact of circular RNAs (circRNAs) on AMI has rarely been recognized and needs to be explored.Materials and MethodsThe circRNA array was applied to investigate the expression level of circRNAs in the blood samples of coronary arteries of three AMI patients and three normal persons. Principal component analysis (PCA) and unsupervised clustering analysis were performed to reveal the distinguished expression patterns of circRNAs. The miRNA expression profiles of AMI patients were identified from a public dataset from the Gene Expression Omnibus (GEO) database (GSE31568). The miRNA binding sites on the circRNAs were predicted by miRanda. The miRNA enrichment analysis and annotation tool were used to explore the pathways that the dysregulated circRNAs may participate in.ResultsIn total, 142 differentially expressed circRNAs, including 89 upregulated and 53 downregulated in AMI samples, were identified by the differential expression analysis. AMI patients had quite different circRNA expression profiles to those of normal controls. Functional characterization revealed that circRNAs that had the potential to regulate miRNAs were mainly involved in seven pathways, such as the Runt-related transcription factor-1 (RUNX1) expression and activity-related pathway. Specifically, hsa_circRNA_001654, hsa_circRNA_091761, hsa_circRNA_405624, and hsa_circRNA_406698 were predicted to sponge four miRNAs including hsa-miR-491-3p, hsa-miR-646, hsa-miR-603, and hsa-miR-922, thereby regulating RUNX1 expression or activity.ConclusionWe identified dysregulated blood circRNAs in the coronary arteries of AMI patients and predicted that four upregulated circRNAs were involved in the regulation of RUNX1 expression or activity through sponging four miRNAs.

scholarly journals SIRT1 contributes to telomere maintenance and augments global homologous recombination

2010 ◽  
Vol 191 (7) ◽  
pp. 1299-1313 ◽  
Author(s):  
Jose A. Palacios ◽  
Daniel Herranz ◽  
Maria Luigia De Bonis ◽  
Susana Velasco ◽  
Manuel Serrano ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Telomerase Activity ◽  
Histone Deacetylation ◽  
Telomere Maintenance ◽  
Loss Of Function ◽  
Entire Genome ◽  
Telomere Shortening ◽  
Telomere Biology ◽  
Sir Complex

Yeast Sir2 deacetylase is a component of the silent information regulator (SIR) complex encompassing Sir2/Sir3/Sir4. Sir2 is recruited to telomeres through Rap1, and this complex spreads into subtelomeric DNA via histone deacetylation. However, potential functions at telomeres for SIRT1, the mammalian orthologue of yeast Sir2, are less clear. We studied both loss of function (SIRT1 deficient) and gain of function (SIRT1super) mouse models. Our results indicate that SIRT1 is a positive regulator of telomere length in vivo and attenuates telomere shortening associated with aging, an effect dependent on telomerase activity. Using chromatin immunoprecipitation assays, we find that SIRT1 interacts with telomeric repeats in vivo. In addition, SIRT1 overexpression increases homologous recombination throughout the entire genome, including telomeres, centromeres, and chromosome arms. These findings link SIRT1 to telomere biology and global DNA repair and provide new mechanistic explanations for the known functions of SIRT1 in protection from DNA damage and some age-associated pathologies.

Sign in / Sign up

Export Citation Format

Share Document