Mutually Exclusive Binding of Telomerase RNA and DNA by Ku Alters Telomerase Recruitment Model

Overview

Journal Cell

Publisher Cell Press

Specialty Cell Biology

Date 2012 Feb 28

PMID 22365814

Citations 60

Authors

Jennifer S Pfingsten

Karen J Goodrich

Cornelius Taabazuing

Faissal Ouenzar

Pascal Chartrand

Thomas R Cech

Affiliations

Soon will be listed here.

Abstract

In Saccharomyces cerevisiae, the Ku heterodimer contributes to telomere maintenance as a component of telomeric chromatin and as an accessory subunit of telomerase. How Ku binding to double-stranded DNA (dsDNA) and to telomerase RNA (TLC1) promotes Ku's telomeric functions is incompletely understood. We demonstrate that deletions designed to constrict the DNA-binding ring of Ku80 disrupt nonhomologous end-joining (NHEJ), telomeric gene silencing, and telomere length maintenance, suggesting that these functions require Ku's DNA end-binding activity. Contrary to the current model, a mutant Ku with low affinity for dsDNA also loses affinity for TLC1 both in vitro and in vivo. Competition experiments reveal that wild-type Ku binds dsDNA and TLC1 mutually exclusively. Cells expressing the mutant Ku are deficient in nuclear accumulation of TLC1, as expected from the RNA-binding defect. These findings force reconsideration of the mechanisms by which Ku assists in recruiting telomerase to natural telomeres and broken chromosome ends. PAPERCLIP:

Citing Articles

telomerase RNA: secondary structure and flexible-scaffold function.

McMurdie K, Peeney A, Mefford M, Baumann P, Zappulla D bioRxiv. 2025; .

PMID: 40027754 PMC: 11870620. DOI: 10.1101/2025.02.22.638514.

A mechanism for telomere-specific telomere length regulation.

Teplitz G, Pasquier E, Bonnell E, De Laurentiis E, Bartle L, Lucier J bioRxiv. 2024; .

PMID: 38915611 PMC: 11195199. DOI: 10.1101/2024.06.12.598646.

DNA-PK participates in pre-rRNA biogenesis independent of DNA double-strand break repair.

Li P, Gai X, Li Q, Yang Q, Yu X Nucleic Acids Res. 2024; 52(11):6360-6375.

PMID: 38682589 PMC: 11194077. DOI: 10.1093/nar/gkae316.

Telomere maintenance in African trypanosomes.

Li B Front Mol Biosci. 2023; 10:1302557.

PMID: 38074093 PMC: 10704157. DOI: 10.3389/fmolb.2023.1302557.

Post-Transcriptional and Post-Translational Modifications in Telomerase Biogenesis and Recruitment to Telomeres.

Shepelev N, Dontsova O, Rubtsova M Int J Mol Sci. 2023; 24(5).

PMID: 36902458 PMC: 10003056. DOI: 10.3390/ijms24055027.

References

Schober H, Ferreira H, Kalck V, Gehlen L, Gasser S . Yeast telomerase and the SUN domain protein Mps3 anchor telomeres and repress subtelomeric recombination. Genes Dev. 2009; 23(8):928-38. PMC: 2675861. DOI: 10.1101/gad.1787509. View

Fisher T, Taggart A, Zakian V . Cell cycle-dependent regulation of yeast telomerase by Ku. Nat Struct Mol Biol. 2004; 11(12):1198-205. DOI: 10.1038/nsmb854. View

Gottschling D, Aparicio O, Billington B, Zakian V . Position effect at S. cerevisiae telomeres: reversible repression of Pol II transcription. Cell. 1990; 63(4):751-62. DOI: 10.1016/0092-8674(90)90141-z. View

Nugent C, Bosco G, ROSS L, Evans S, Salinger A, Moore J . Telomere maintenance is dependent on activities required for end repair of double-strand breaks. Curr Biol. 1998; 8(11):657-60. DOI: 10.1016/s0960-9822(98)70253-2. View

Blier P, Griffith A, Craft J, Hardin J . Binding of Ku protein to DNA. Measurement of affinity for ends and demonstration of binding to nicks. J Biol Chem. 1993; 268(10):7594-601. View

Greider C, Blackburn E . A telomeric sequence in the RNA of Tetrahymena telomerase required for telomere repeat synthesis. Nature. 1989; 337(6205):331-7. DOI: 10.1038/337331a0. View

Gravel S, Larrivee M, Labrecque P, Wellinger R . Yeast Ku as a regulator of chromosomal DNA end structure. Science. 1998; 280(5364):741-4. DOI: 10.1126/science.280.5364.741. View

Mozdy A, Podell E, Cech T . Multiple yeast genes, including Paf1 complex genes, affect telomere length via telomerase RNA abundance. Mol Cell Biol. 2008; 28(12):4152-61. PMC: 2423132. DOI: 10.1128/MCB.00512-08. View

Lopez C, Ribes-Zamora A, Indiviglio S, Williams C, Haricharan S, Bertuch A . Ku must load directly onto the chromosome end in order to mediate its telomeric functions. PLoS Genet. 2011; 7(8):e1002233. PMC: 3154960. DOI: 10.1371/journal.pgen.1002233. View

10.

Dynan W, Yoo S . Interaction of Ku protein and DNA-dependent protein kinase catalytic subunit with nucleic acids. Nucleic Acids Res. 1998; 26(7):1551-9. PMC: 147477. DOI: 10.1093/nar/26.7.1551. View

11.

Bianchi A, de Lange T . Ku binds telomeric DNA in vitro. J Biol Chem. 1999; 274(30):21223-7. DOI: 10.1074/jbc.274.30.21223. View

12.

Lee S, Paques F, Sylvan J, Haber J . Role of yeast SIR genes and mating type in directing DNA double-strand breaks to homologous and non-homologous repair paths. Curr Biol. 1999; 9(14):767-70. DOI: 10.1016/s0960-9822(99)80339-x. View

13.

Peterson S, Stellwagen A, Diede S, Singer M, Haimberger Z, Johnson C . The function of a stem-loop in telomerase RNA is linked to the DNA repair protein Ku. Nat Genet. 2001; 27(1):64-7. DOI: 10.1038/83778. View

14.

Gallardo F, Olivier C, Dandjinou A, Wellinger R, Chartrand P . TLC1 RNA nucleo-cytoplasmic trafficking links telomerase biogenesis to its recruitment to telomeres. EMBO J. 2008; 27(5):748-57. PMC: 2265757. DOI: 10.1038/emboj.2008.21. View

15.

Porter S, Greenwell P, Ritchie K, Petes T . The DNA-binding protein Hdf1p (a putative Ku homologue) is required for maintaining normal telomere length in Saccharomyces cerevisiae. Nucleic Acids Res. 1996; 24(4):582-5. PMC: 145698. DOI: 10.1093/nar/24.4.582. View

16.

Pennaneach V, Putnam C, Kolodner R . Chromosome healing by de novo telomere addition in Saccharomyces cerevisiae. Mol Microbiol. 2006; 59(5):1357-68. DOI: 10.1111/j.1365-2958.2006.05026.x. View

17.

Chen X, Tomkinson A . Yeast Nej1 is a key participant in the initial end binding and final ligation steps of nonhomologous end joining. J Biol Chem. 2010; 286(6):4931-40. PMC: 3039407. DOI: 10.1074/jbc.M110.195024. View

18.

Teixeira M, Arneric M, Sperisen P, Lingner J . Telomere length homeostasis is achieved via a switch between telomerase- extendible and -nonextendible states. Cell. 2004; 117(3):323-35. DOI: 10.1016/s0092-8674(04)00334-4. View

19.

Riha K, Heacock M, Shippen D . The role of the nonhomologous end-joining DNA double-strand break repair pathway in telomere biology. Annu Rev Genet. 2006; 40:237-77. DOI: 10.1146/annurev.genet.39.110304.095755. View

20.

Bertuch A, Lundblad V . The Ku heterodimer performs separable activities at double-strand breaks and chromosome termini. Mol Cell Biol. 2003; 23(22):8202-15. PMC: 262345. DOI: 10.1128/MCB.23.22.8202-8215.2003. View