2023
Pot1b −/− 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 mechanismMutations
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
2020
Microcephalin 1/BRIT1-TRF2 interaction promotes telomere replication and repair, linking telomere dysfunction to primary microcephaly
Cicconi A, Rai R, Xiong X, Broton C, Al-Hiyasat A, Hu C, Dong S, Sun W, Garbarino J, Bindra RS, Schildkraut C, Chen Y, Chang S. Microcephalin 1/BRIT1-TRF2 interaction promotes telomere replication and repair, linking telomere dysfunction to primary microcephaly. Nature Communications 2020, 11: 5861. PMID: 33203878, PMCID: PMC7672075, DOI: 10.1038/s41467-020-19674-0.Peer-Reviewed Original ResearchAminopeptidasesAnimalsBinding SitesCalorimetryCell Cycle ProteinsCytoskeletal ProteinsDipeptidyl-Peptidases and Tripeptidyl-PeptidasesDNA DamageFibroblastsHeLa CellsHistonesHumansMiceMicrocephalyMutationProtein Interaction Domains and MotifsSerine ProteasesShelterin ComplexTelomereTelomere-Binding ProteinsTelomeric Repeat Binding Protein 2
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 portionMutationsDomainMutantsTelomeresCytogenetic Analysis of Telomere Dysfunction
Rai R, Multani AS, Chang S. Cytogenetic Analysis of Telomere Dysfunction. Methods In Molecular Biology 2017, 1587: 127-131. PMID: 28324504, DOI: 10.1007/978-1-4939-6892-3_12.Peer-Reviewed Original ResearchProbing 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
Pot1 OB-fold mutations unleash telomere instability to initiate tumorigenesis
Gu P, Wang Y, Bisht KK, Wu L, Kukova L, Smith EM, Xiao Y, Bailey SM, Lei M, Nandakumar J, Chang S. Pot1 OB-fold mutations unleash telomere instability to initiate tumorigenesis. Oncogene 2016, 36: 1939-1951. PMID: 27869160, PMCID: PMC5383532, DOI: 10.1038/onc.2016.405.Peer-Reviewed Original ResearchConceptsComplex cytogenetic rearrangementsHuman cancersInvasive breast carcinomaAberrant DNA damageMouse mammary epitheliumBreast carcinomaMammary epitheliumHematopoietic malignanciesConditional deletionAlternative non-homologous endChromosomal aberrationsCancer initiationRepair responseFamilial mutationsOncogenic mutationsCytogenetic rearrangementsTumorigenesisCancerDNA damageMutationsGenetic changesCarcinomaDNA damage responseMalignancyDysfunctional telomeres induce p53‐dependent and independent apoptosis to compromise cellular proliferation and inhibit tumor formation
Wang Y, Wang X, Flores ER, Yu J, Chang S. Dysfunctional telomeres induce p53‐dependent and independent apoptosis to compromise cellular proliferation and inhibit tumor formation. Aging Cell 2016, 15: 646-660. PMID: 27113195, PMCID: PMC4933665, DOI: 10.1111/acel.12476.Peer-Reviewed Original ResearchTRF2-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
2014
Synergistic tumor suppression by combined inhibition of telomerase and CDKN1A
Gupta R, Dong Y, Solomon PD, Wettersten HI, Cheng CJ, Min JN, Henson J, Dogra SK, Hwang SH, Hammock BD, Zhu LJ, Reddel RR, Saltzman WM, Weiss RH, Chang S, Green MR, Wajapeyee N. Synergistic tumor suppression by combined inhibition of telomerase and CDKN1A. Proceedings Of The National Academy Of Sciences Of The United States Of America 2014, 111: e3062-e3071. PMID: 25024194, PMCID: PMC4121806, DOI: 10.1073/pnas.1411370111.Peer-Reviewed Original ResearchConceptsP53-mediated transcriptional activationCyclin-dependent kinase inhibitor 1AMutant p53Telomerase inhibitionTumor suppressor p53Transcriptional activationSynergistic tumor suppressionTelomere dysfunctionCheckpoint proteinsP53 upregulated modulatorTumor suppressionCDK inhibitorsSuppressor p53Inhibitor 1AP53 activityTelomeraseHuman cancersCancer cell linesApoptosis inductionPharmacological inhibitionApoptosisCell linesPharmacological restorationP21Growth inhibitionPot1a Prevents Telomere Dysfunction and ATM-Dependent Neuronal Loss
Lee Y, Brown EJ, Chang S, McKinnon PJ. Pot1a Prevents Telomere Dysfunction and ATM-Dependent Neuronal Loss. Journal Of Neuroscience 2014, 34: 7836-7844. PMID: 24899707, PMCID: PMC4044246, DOI: 10.1523/jneurosci.4245-13.2014.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAnimals, NewbornAtaxia Telangiectasia Mutated ProteinsBeta-GalactosidaseBrainCell CycleCell Cycle ProteinsCells, CulturedDNA DamageDNA-Binding ProteinsEmbryo, MammalianFemaleGene Expression RegulationMaleMiceMice, TransgenicNestinNeuronsShelterin ComplexTelomereTelomere-Binding Proteins
2013
p16INK4a protects against dysfunctional telomere–induced ATR-dependent DNA damage responses
Wang Y, Sharpless N, Chang S. p16INK4a protects against dysfunctional telomere–induced ATR-dependent DNA damage responses. Journal Of Clinical Investigation 2013, 123: 4489-4501. PMID: 24091330, PMCID: PMC3784543, DOI: 10.1172/jci69574.Peer-Reviewed Original ResearchMeSH KeywordsAgingAnimalsApoptosisAtaxia Telangiectasia Mutated ProteinsBone Marrow TransplantationCell ProliferationCells, CulturedCyclin-Dependent Kinase Inhibitor p16Cyclin-Dependent Kinase Inhibitor p21DNA DamageDNA RepairDNA-Binding ProteinsFemaleHematopoiesisHematopoietic Stem CellsIntestine, SmallMaleMiceMice, SCIDMice, TransgenicProtein StabilitySequence DeletionSpleenTelomereTelomere HomeostasisTumor Suppressor Protein p53ConceptsHematopoietic cellsDeletion of p21P21-dependent cell cycle arrestOrgan impairmentTelomere dysfunctionCell cycle arrestMouse modelDNA damage responseSmall intestineFunctional defectsCell functionProliferative capacityP53-dependent apoptosisCycle arrestDysfunctional telomeresCellular senescenceDysfunctionP53-dependent DNA damage responseProliferative cellsHematopoietic systemProtective functionTumor suppressorProliferative defectP53 stabilizationCellsFunctional 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 mutationThe mINO80 chromatin remodeling complex is required for efficient telomere replication and maintenance of genome stability
Min JN, Tian Y, Xiao Y, Wu L, Li L, Chang S. The mINO80 chromatin remodeling complex is required for efficient telomere replication and maintenance of genome stability. Cell Research 2013, 23: 1396-1413. PMID: 23979016, PMCID: PMC3847565, DOI: 10.1038/cr.2013.113.Peer-Reviewed Original ResearchMeSH KeywordsAllelesAnimalsCells, CulturedCellular SenescenceChromatinChromatin Assembly and DisassemblyDNA Breaks, Double-StrandedDNA HelicasesDNA RepairDNA ReplicationFibroblastsGenomic InstabilityHydroxyureaMiceMice, Inbred C57BLMice, KnockoutMutationNucleic Acid Synthesis InhibitorsTelomereTumor Suppressor Protein p53ConceptsHomology-directed DNA repairEfficient telomere replicationGenome stabilityTelomere replicationDependent DNA damage responseDNA double-strand breaksDNA damage responseDNA damage fociMammalian cell linesATPase catalytic subunitConditional knockout approachDouble-strand breaksINO80 chromatinChromatin remodelingOrganismal functionTranscriptional regulationFragile telomeresDamage responseDNA replicationCatalytic subunitDamage fociDysfunctional telomeresSingle-strand DNADNA repairKnockout approachSingle 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
Cooperation between p53 and the telomere-protecting shelterin component Pot1a in endometrial carcinogenesis
Akbay EA, Peña CG, Ruder D, Michel JA, Nakada Y, Pathak S, Multani AS, Chang S, Castrillon DH. Cooperation between p53 and the telomere-protecting shelterin component Pot1a in endometrial carcinogenesis. Oncogene 2012, 32: 2211-2219. PMID: 22689059, PMCID: PMC3636499, DOI: 10.1038/onc.2012.232.Peer-Reviewed Original ResearchMeSH KeywordsAneuploidyAnimalsCarcinoma, EndometrioidCell Transformation, NeoplasticDisease Models, AnimalDNA Breaks, Double-StrandedDNA-Binding ProteinsEndometrial NeoplasmsFemaleHumansMiceMice, TransgenicShelterin ComplexTelomere HomeostasisTelomere-Binding ProteinsTumor Cells, CulturedTumor Suppressor Protein p53ConceptsType II endometrial cancerEndometrial intraepithelial carcinomaEndometrial cancerEndometrial adenocarcinomaEndometrial carcinogenesisTelomerase-null miceProminent nuclear atypiaType II tumorsMulti-organ failureType II cancersInvasive endometrial adenocarcinomaMonths of ageMetastatic diseaseII tumorsEndometrial lesionsIntraepithelial carcinomaEndometrial epitheliumNuclear atypiaTumorsAdenocarcinomaVivo correlatesDetectable DNA damageHuman tumorsMiceLesionsCTC1 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 role
2011
The E3 ubiquitin ligase Rnf8 stabilizes Tpp1 to promote telomere end protection
Rai R, Li JM, Zheng H, Lok GT, Deng Y, Huen MS, Chen J, Jin J, Chang S. The E3 ubiquitin ligase Rnf8 stabilizes Tpp1 to promote telomere end protection. Nature Structural & Molecular Biology 2011, 18: 1400-1407. PMID: 22101936, PMCID: PMC3657743, DOI: 10.1038/nsmb.2172.Peer-Reviewed Original Research