2023
Telomeres cooperate with the nuclear envelope to maintain genome stability
Rai R, Sodeinde T, Boston A, Chang S. Telomeres cooperate with the nuclear envelope to maintain genome stability. BioEssays 2023, 46: e2300184. PMID: 38047499, DOI: 10.1002/bies.202300184.Peer-Reviewed Original ResearchNuclear envelopeGenome stabilityNuclear envelope ruptureKu70/Ku80Homology-directed recombinationMammalian telomeresChromosome stabilityNuclear laminsShelterin componentsProtein TRF2Envelope ruptureRepair proteinsTelomeresRap1Recent findingsProteinFunction resultsRecombinationDNA sensingForm structuresLaminsTRF2Ku80DNAHomeostasisPot1b −/− tumors activate G-quadruplex-induced DNA damage to promote telomere hyper-elongation
Takasugi T, Gu P, Liang F, Staco I, Chang S. Pot1b −/− tumors activate G-quadruplex-induced DNA damage to promote telomere hyper-elongation. Nucleic Acids Research 2023, 51: 9227-9247. PMID: 37560909, PMCID: PMC10516629, DOI: 10.1093/nar/gkad648.Peer-Reviewed Original ResearchConceptsDNA damage responseDamage responseReplication protein A (RPA) complexDependent DNA damage responseTelomere length homeostasisTelomere maintenance mechanismLength homeostasisTelomerase recruitmentPOT1 proteinsHuman POT1Mouse genomeLength maintenanceFunction disruptsReplicative immortalityTelomeresPOT1 mutationsDNA damageHuman cancersLonger telomeresPOT1bMaintenance mechanismsSerial transplantationA complexesSimilar mechanismMutationsHomology directed telomere clustering, ultrabright telomere formation and nuclear envelope rupture in cells lacking TRF2B and RAP1
Rai R, Biju K, Sun W, Sodeinde T, Al-Hiyasat A, Morgan J, Ye X, Li X, Chen Y, Chang S. Homology directed telomere clustering, ultrabright telomere formation and nuclear envelope rupture in cells lacking TRF2B and RAP1. Nature Communications 2023, 14: 2144. PMID: 37059728, PMCID: PMC10104862, DOI: 10.1038/s41467-023-37761-w.Peer-Reviewed Original ResearchConceptsDouble-strand breaksNuclear envelopeDistinct DNA repair mechanismsNuclear envelope ruptureKu70/Ku80DNA repair mechanismsDNA-RNA hybridsBRCT domainGenome stabilityPhosphomimetic mutantTelomere formationGenotoxic stressEnvelope ruptureDysfunctional telomeresBasic domainRap1Aberrant laminTelomeresRepair mechanismsLaminsTRF2HomologyProteinShelterinADAR1p110
2021
Distinct functions of POT1 proteins contribute to the regulation of telomerase recruitment to telomeres
Gu P, Jia S, Takasugi T, Tesmer VM, Nandakumar J, Chen Y, Chang S. Distinct functions of POT1 proteins contribute to the regulation of telomerase recruitment to telomeres. Nature Communications 2021, 12: 5514. PMID: 34535663, PMCID: PMC8448735, DOI: 10.1038/s41467-021-25799-7.Peer-Reviewed Original ResearchConceptsDNA damage responseTelomerase recruitmentPOT1 proteinsDamage responseATR-dependent DNA damage responseNon-homologous end-joining DNA repair pathwayRecruitment of telomeraseC-strand fillAmino acidsDNA repair pathwaysUnique amino acidsTEN1 (CST) complexTelomere extensionCTC1-STN1Stable heterodimerRepair pathwaysC-terminusDistinct functionsPOT1bPOT1aTelomeresC-strandG-strandTPP1Protein
2019
The Replisome Mediates A-NHEJ Repair of Telomeres Lacking POT1-TPP1 Independently of MRN Function
Rai R, Gu P, Broton C, Kumar-Sinha C, Chen Y, Chang S. The Replisome Mediates A-NHEJ Repair of Telomeres Lacking POT1-TPP1 Independently of MRN Function. Cell Reports 2019, 29: 3708-3725.e5. PMID: 31825846, PMCID: PMC7001145, DOI: 10.1016/j.celrep.2019.11.012.Peer-Reviewed Original ResearchMeSH KeywordsAcid Anhydride HydrolasesAdaptor Proteins, Signal TransducingAminopeptidasesAnimalsCell Cycle ProteinsCell Line, TumorCells, CulturedCheckpoint Kinase 1Dipeptidyl-Peptidases and Tripeptidyl-PeptidasesDNA End-Joining RepairDNA Repair EnzymesDNA-Binding ProteinsDNA-Directed DNA PolymeraseExodeoxyribonucleasesHEK293 CellsHumansMiceMRE11 Homologue ProteinMultienzyme ComplexesProliferating Cell Nuclear AntigenSerine ProteasesShelterin ComplexTelomereTelomere-Binding ProteinsTelomeric Repeat Binding Protein 2ConceptsReplication protein AReplisome complexPOT1-TPP1Dysfunctional telomeresDNA damage sensor MRE11-RAD50DNA damage checkpoint responseAlternative non-homologous endNon-homologous endMRN functionChromosome endsMre11-Rad50Checkpoint responseDNA-PKTelomeric overhangMre11 nucleaseTelomere repairEnd resectionRAD-51Repair pathwaysAtaxia telangiectasiaTelomeresC-strandDNA damageReplisomeClaspin
2017
Structural and functional analyses of the mammalian TIN2-TPP1-TRF2 telomeric complex
Hu C, Rai R, Huang C, Broton C, Long J, Xu Y, Xue J, Lei M, Chang S, Chen Y. Structural and functional analyses of the mammalian TIN2-TPP1-TRF2 telomeric complex. Cell Research 2017, 27: 1485-1502. PMID: 29160297, PMCID: PMC5717407, DOI: 10.1038/cr.2017.144.Peer-Reviewed Original ResearchConceptsShelterin complexTelomeric DNAStructure-based mutagenesis analysisProtein-protein interaction platformRepetitive DNA sequencesTelomere end protectionN-terminal domainMammalian telomeresChromosome endsTelomeric complexNucleoprotein complexesMutagenesis analysisEnd protectionDNA sequencesLike domainHeterodimer bindsTIN2Functional analysisMolecular mechanismsTRF2TPP1Stable assemblyEssential roleTRF1TelomeresStructural insights into POT1-TPP1 interaction and POT1 C-terminal mutations in human cancer
Chen C, Gu P, Wu J, Chen X, Niu S, Sun H, Wu L, Li N, Peng J, Shi S, Fan C, Huang M, Wong CC, Gong Q, Kumar-Sinha C, Zhang R, Pusztai L, Rai R, Chang S, Lei M. Structural insights into POT1-TPP1 interaction and POT1 C-terminal mutations in human cancer. Nature Communications 2017, 8: 14929. PMID: 28393832, PMCID: PMC5394241, DOI: 10.1038/ncomms14929.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAnimalsConserved SequenceDNA DamageDNA Mutational AnalysisDNA RepairGenomic InstabilityHumansMiceModels, MolecularMolecular ChaperonesMutationNeoplasmsPhosphoproteinsProstaglandin-E SynthasesProtein BindingProtein Structure, SecondaryScattering, Small AngleShelterin ComplexStructure-Activity RelationshipTelomere-Binding ProteinsX-Ray DiffractionConceptsTelomerase-mediated telomere extensionHuman cancersDNA damage responseC-terminal mutationsOB foldsHuman POT1Chromosome endsGenome instabilityPOT1-TPP1Telomere extensionDamage responseStable heterodimerA-NHEJStructural insightsC-terminusInappropriate repairTPP1POT1Heart-shaped structureMissense mutationsTerminal portionMutationsDomainMutantsTelomeresProbing the Telomere Damage Response
Rai R, Chang S. Probing the Telomere Damage Response. Methods In Molecular Biology 2017, 1587: 133-138. PMID: 28324505, DOI: 10.1007/978-1-4939-6892-3_13.Peer-Reviewed Original ResearchConceptsTelomere dysfunctionDNA damage response signalsDNA damage repair pathwaysTelomere damage responseΓ-H2AXDamage repair pathwaysCheckpoint sensorNbs1 complexReplicative attritionMre11-Rad50Shelterin componentsDamage responseTelomeric DNADysfunctional telomeresRepair pathwaysDownstream effectorsComplete deletionTelomeresDNAPathwayTRF2Chk2Chk1KinaseEffectors
2016
TRF2-RAP1 is required to protect telomeres from engaging in homologous recombination-mediated deletions and fusions
Rai R, Chen Y, Lei M, Chang S. TRF2-RAP1 is required to protect telomeres from engaging in homologous recombination-mediated deletions and fusions. Nature Communications 2016, 7: 10881. PMID: 26941064, PMCID: PMC4785230, DOI: 10.1038/ncomms10881.Peer-Reviewed Original ResearchConceptsRepressor/activator protein 1Telomere length controlTranscriptional gene regulationRepair of telomeresTelomere end protectionNon-homologous endActivator protein-1Myb domainChromosome fusionsYeast Rap1Gene regulationHDR pathwayEnd protectionBasic domainTelomere lossTelomeresHuman cellsHR factorsProtein 1Length controlPARP1Free fusionInappropriate processingTRF2Important role
2015
Monitoring the DNA Damage Response at Dysfunctional Telomeres
Rai R, Chang S. Monitoring the DNA Damage Response at Dysfunctional Telomeres. Methods In Molecular Biology 2015, 1343: 175-180. PMID: 26420717, DOI: 10.1007/978-1-4939-2963-4_14.Peer-Reviewed Original ResearchConceptsDysfunctional telomeresDNA damage sensorDNA damage responseDNA damage fociSitu hybridization approachEukaryotic chromosomesShelterin componentsDNA repeatsGenomic stabilityDDR proteinsDamage responseTelomeric DNADDR pathwaysDamage fociChromosomal endsTelomere dysfunctionDamage sensorTelomeresDNA damageHybridization approachCellular viabilityPathwayProper maintenanceChromosomesRepeats
2013
SLX4 Assembles a Telomere Maintenance Toolkit by Bridging Multiple Endonucleases with Telomeres
Wan B, Yin J, Horvath K, Sarkar J, Chen Y, Wu J, Wan K, Lu J, Gu P, Yu EY, Lue NF, Chang S, Liu Y, Lei M. SLX4 Assembles a Telomere Maintenance Toolkit by Bridging Multiple Endonucleases with Telomeres. Cell Reports 2013, 4: 861-869. PMID: 24012755, PMCID: PMC4334113, DOI: 10.1016/j.celrep.2013.08.017.Peer-Reviewed Original ResearchConceptsTRFH domainRecombination-based telomere maintenanceTelomeric protein TRF2Nucleolytic resolutionTelomeric localizationMultiple endonucleasesPeptide-binding siteDNA metabolismProtein TRF2Telomere maintenanceSLX4TRF2Molecular mechanismsDNA structureHuman cellsTelomeresSLX1Protein levelsEndonucleaseMotifMus81ComplexesNucleaseXPFDomainFunctional characterization of human CTC1 mutations reveals novel mechanisms responsible for the pathogenesis of the telomere disease Coats plus
Gu P, Chang S. Functional characterization of human CTC1 mutations reveals novel mechanisms responsible for the pathogenesis of the telomere disease Coats plus. Aging Cell 2013, 12: 1100-1109. PMID: 23869908, PMCID: PMC4083614, DOI: 10.1111/acel.12139.Peer-Reviewed Original ResearchConceptsCTC1 mutationsFrameshift mutantsTelomere dysfunctionUnstable protein productsDNA/protein structuresFirst biochemical characterizationDNA PolαStn1-Ten1CST complexFused chromosomeGenome stabilityTelomere functionTelomere replicationMissense mutantsCTC1-STN1Functional characterizationBiochemical characterizationProtein productsProtein structureRare recessive disorderTelomeresMutantsMissense mutationsNovel mechanismFrameshift mutationSingle strand DNA binding proteins 1 and 2 protect newly replicated telomeres
Gu P, Deng W, Lei M, Chang S. Single strand DNA binding proteins 1 and 2 protect newly replicated telomeres. Cell Research 2013, 23: 705-719. PMID: 23459151, PMCID: PMC3641597, DOI: 10.1038/cr.2013.31.Peer-Reviewed Original ResearchMeSH KeywordsAllelesAnimalsCell LineChromatidsDNA DamageDNA RepairDNA-Binding ProteinsDNA, Single-StrandedGenomic InstabilityHumansMiceMice, KnockoutMitochondrial ProteinsProtein BindingRadiation, IonizingRNA InterferenceRNA, Small InterferingShelterin ComplexTelomereTelomere-Binding ProteinsTelomeric Repeat Binding Protein 2ConceptsGenome stabilitySingle-strand DNAHeterotrimeric protein complexDNA damage responseTelomere end protectionProtein 1Subset of telomeresTelomeric ssDNAProtein complexesTelomeric DNADamage responseG-overhangsEnd protectionConditional knockout miceTelomeresΔ miceDNAPOT1aDevelopmental abnormalitiesStrand DNACritical roleKnockout miceINTS3F allelePOT1b
2012
CTC1 deletion results in defective telomere replication, leading to catastrophic telomere loss and stem cell exhaustion
Gu P, Min J, Wang Y, Huang C, Peng T, Chai W, Chang S. CTC1 deletion results in defective telomere replication, leading to catastrophic telomere loss and stem cell exhaustion. The EMBO Journal 2012, 31: 2309-2321. PMID: 22531781, PMCID: PMC3364752, DOI: 10.1038/emboj.2012.96.Peer-Reviewed Original ResearchConceptsMammalian CSTTelomere lossDefective telomere replicationDeletion resultsG2/M checkpointComplete bone marrow failureStem cell exhaustionTelomere deprotectionGenome stabilityTEN1 (CST) complexTelomere replicationReplication forksTelomere maintenanceLength maintenanceCTC1-STN1Efficient restartM checkpointVivo functionCTC1TelomeresAcute deletionBone marrow failureProliferative defectEfficient replicationEssential roleRPA and POT1
Flynn RL, Chang S, Zou L. RPA and POT1. Cell Cycle 2012, 11: 652-657. PMID: 22373525, PMCID: PMC3318101, DOI: 10.4161/cc.11.4.19061.Peer-Reviewed Original ResearchConceptsReplication protein ATelomere maintenanceDNA replicationProtein complex shelterinTTAGGG telomeric repeatsTelomeric ssDNACheckpoint responseTelomeric repeatsPOT1Ataxia telangiectasiaCell cycleAberrant accumulationCycling cellsSpecific mannerInteresting modelTelomeresProtein ACritical roleProteinRecent studiesReplicationShelterinRad3KinaseRepeats
2011
Probing the Telomere Damage Response
Rai R, Chang S. Probing the Telomere Damage Response. Methods In Molecular Biology 2011, 735: 145-150. PMID: 21461819, PMCID: PMC3690558, DOI: 10.1007/978-1-61779-092-8_14.Peer-Reviewed Original ResearchConceptsTelomere dysfunctionDNA damage response signalsDNA damage repair pathwaysTelomere damage responseΓ-H2AXDamage repair pathwaysCheckpoint sensorNbs1 complexReplicative attritionMre11-Rad50Shelterin componentsDamage responseTelomeric DNADysfunctional telomeresRepair pathwaysDownstream effectorsComplete deletionTelomeresDNAPathwayTRF2Chk2Chk1KinaseEffectorsA conserved motif within RAP1 has diversified roles in telomere protection and regulation in different organisms
Chen Y, Rai R, Zhou ZR, Kanoh J, Ribeyre C, Yang Y, Zheng H, Damay P, Wang F, Tsujii H, Hiraoka Y, Shore D, Hu HY, Chang S, Lei M. A conserved motif within RAP1 has diversified roles in telomere protection and regulation in different organisms. Nature Structural & Molecular Biology 2011, 18: 213-221. PMID: 21217703, PMCID: PMC3688267, DOI: 10.1038/nsmb.1974.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid MotifsAmino Acid SequenceAnimalsCells, CulturedCrystallography, X-RayFungal ProteinsHeLa CellsHumansModels, MolecularMolecular Sequence DataMutationNuclear Magnetic Resonance, BiomolecularProtein BindingProtein Interaction Domains and MotifsSaccharomycetalesSchizosaccharomycesShelterin ComplexTelomereTelomere-Binding ProteinsTelomeric Repeat Binding Protein 2ConceptsRap1 C-terminusDifferent interacting partnersProtein Rap1Fission yeastTelomere protectionInteracting partnerTranscriptional silencingDifferent organismsC-terminusFunctional analysisInteraction moduleYeastRap1Different functionsOrganismsTaz1Sir3TRF2MammalianTelomeresSilencingMammalsMotifCrystal structureRegulation
2010
The telomeric protein SNM1B/Apollo is required for normal cell proliferation and embryonic development
Akhter S, Lam YC, Chang S, Legerski RJ. The telomeric protein SNM1B/Apollo is required for normal cell proliferation and embryonic development. Aging Cell 2010, 9: 1047-1056. PMID: 20854421, PMCID: PMC3719988, DOI: 10.1111/j.1474-9726.2010.00631.x.Peer-Reviewed Original ResearchConceptsMutant mouse embryonic fibroblastsSNM1B/ApolloCell proliferation defectMouse embryonic fibroblastsNormal cell proliferationDevelopmental failureHomozygous null miceEnd fusionsProliferation defectEmbryonic developmentGenomic instabilityEmbryonic fibroblastsTelomeric endDevelopmental defectsCell deathVivo roleCell proliferationImpaired proliferationTelomeresNull miceMutant miceThe telomere protein tankyrase 1 regulates DNA damage responses at telomeres
Chang S. The telomere protein tankyrase 1 regulates DNA damage responses at telomeres. Aging 2010, 2: 639-642. PMID: 21076181, PMCID: PMC2993793, DOI: 10.18632/aging.100221.Peer-Reviewed Original ResearchDefending the end zone: Studying the players involved in protecting chromosome ends
Chan SS, Chang S. Defending the end zone: Studying the players involved in protecting chromosome ends. FEBS Letters 2010, 584: 3773-3778. PMID: 20579983, PMCID: PMC3657741, DOI: 10.1016/j.febslet.2010.06.016.Peer-Reviewed Original Research