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Li X, Wang M, Zheng W, Huang W, Wang Z, Jin K, Liu L, Yu Z. Dynamics of TRF1 organizing a single human telomere. Nucleic Acids Res 2021; 49:760-775. [PMID: 33347580 PMCID: PMC7826288 DOI: 10.1093/nar/gkaa1222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/27/2020] [Accepted: 12/04/2020] [Indexed: 11/13/2022] Open
Abstract
Chromosome stability is primarily determined by telomere length. TRF1 is the core subunit of shelterin that plays a critical role in telomere organization and replication. However, the dynamics of TRF1 in scenarios of telomere-processing activities remain elusive. Using single-molecule magnetic tweezers, we here investigated the dynamics of TRF1 upon organizing a human telomere and the protein-DNA interactions at a moving telomeric fork. We first developed a method to obtain telomeres from human cells for directly measuring the telomere length by single-molecule force spectroscopy. Next, we examined the compaction and decompaction of a telomere by TRF1 dimers. TRF1 dissociates from a compacted telomere with heterogenous loops in ∼20 s. We also found a negative correlation between the number of telomeric loops and loop sizes. We further characterized the dynamics of TRF1 at a telomeric DNA fork. With binding energies of 11 kBT, TRF1 can modulate the forward and backward steps of DNA fork movements by 2-9 s at a critical force of F1/2, temporarily maintaining the telomeric fork open. Our results shed light on the mechanisms of how TRF1 organizes human telomeres and facilitates the efficient replication of telomeric DNA. Our work will help future research on the chemical biology of telomeres and shelterin-targeted drug discovery.
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Affiliation(s)
- Xu Li
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Meijie Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Wei Zheng
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Wei Huang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Zeyu Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Kairang Jin
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Zhongbo Yu
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
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Yu EY, Zahid SS, Ganduri S, Sutherland JH, Hsu M, Holloman WK, Lue NF. Structurally distinct telomere-binding proteins in Ustilago maydis execute non-overlapping functions in telomere replication, recombination, and protection. Commun Biol 2020; 3:777. [PMID: 33328546 PMCID: PMC7744550 DOI: 10.1038/s42003-020-01505-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 11/20/2020] [Indexed: 11/09/2022] Open
Abstract
Duplex telomere binding proteins exhibit considerable structural and functional diversity in fungi. Herein we interrogate the activities and functions of two Myb-containing, duplex telomere repeat-binding factors in Ustilago maydis, a basidiomycete that is evolutionarily distant from the standard fungi. These two telomere-binding proteins, UmTay1 and UmTrf2, despite having distinct domain structures, exhibit comparable affinities and sequence specificity for the canonical telomere repeats. UmTay1 specializes in promoting telomere replication and an ALT-like pathway, most likely by modulating the helicase activity of Blm. UmTrf2, in contrast, is critical for telomere protection; transcriptional repression of Umtrf2 leads to severe growth defects and profound telomere aberrations. Comparative analysis of UmTay1 homologs in different phyla reveals broad functional diversity for this protein family and provides a case study for how DNA-binding proteins can acquire and lose functions at various chromosomal locations. Our findings also point to stimulatory effect of telomere protein on ALT in Ustilago maydis that may be conserved in other systems.
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Affiliation(s)
- Eun Young Yu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Syed S Zahid
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Swapna Ganduri
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Jeanette H Sutherland
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Min Hsu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - William K Holloman
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Neal F Lue
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA. .,Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA.
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Méndez-Pertuz M, Martínez P, Blanco-Aparicio C, Gómez-Casero E, Belen García A, Martínez-Torrecuadrada J, Palafox M, Cortés J, Serra V, Pastor J, Blasco MA. Modulation of telomere protection by the PI3K/AKT pathway. Nat Commun 2017; 8:1278. [PMID: 29097657 PMCID: PMC5668434 DOI: 10.1038/s41467-017-01329-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 09/11/2017] [Indexed: 11/23/2022] Open
Abstract
Telomeres and the insulin/PI3K pathway are considered hallmarks of aging and cancer. Here, we describe a role for PI3K/AKT in the regulation of TRF1, an essential component of the shelterin complex. PI3K and AKT chemical inhibitors reduce TRF1 telomeric foci and lead to increased telomeric DNA damage and fragility. We identify the PI3Kα isoform as responsible for this TRF1 inhibition. TRF1 is phosphorylated at different residues by AKT and these modifications regulate TRF1 protein stability and TRF1 binding to telomeric DNA in vitro and are important for in vivo TRF1 telomere location and cell viability. Patient-derived breast cancer PDX mouse models that effectively respond to a PI3Kα specific inhibitor, BYL719, show decreased TRF1 levels and increased DNA damage. These findings functionally connect two of the major pathways for cancer and aging, telomeres and the PI3K pathway, and pinpoint PI3K and AKT as novel targets for chemical modulation of telomere protection. Regulation of telomeres and the insulin/PI3K pathway both have roles in aging and cancer development but have not been functionally linked. Here the authors demonstrate that PI3K, via downstream targets, regulates TRF1 via phosphorylation.
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Affiliation(s)
- Marinela Méndez-Pertuz
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, E-28029, Spain
| | - Paula Martínez
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, E-28029, Spain
| | - Carmen Blanco-Aparicio
- Experimental Therapeutics Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, E-28029, Spain
| | - Elena Gómez-Casero
- Experimental Therapeutics Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, E-28029, Spain
| | - Ana Belen García
- Experimental Therapeutics Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, E-28029, Spain
| | - Jorge Martínez-Torrecuadrada
- Biotechnology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, E-28029, Spain
| | - Marta Palafox
- Experimental Therapeutics Group, Vall d´Hebron Institute of Oncology (VHIO), Natzaret 115-117, Barcelona, E-08035, Spain
| | - Javier Cortés
- Experimental Therapeutics Group, Vall d´Hebron Institute of Oncology (VHIO), Natzaret 115-117, Barcelona, E-08035, Spain
| | - Violeta Serra
- Experimental Therapeutics Group, Vall d´Hebron Institute of Oncology (VHIO), Natzaret 115-117, Barcelona, E-08035, Spain
| | - Joaquin Pastor
- Experimental Therapeutics Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, E-28029, Spain
| | - Maria A Blasco
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, E-28029, Spain.
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