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Semi-conservative DNA replication through telomeres requires Taz1

Abstract

Telomere replication is achieved through the combined action of the conventional DNA replication machinery and the reverse transcriptase, telomerase. Telomere-binding proteins have crucial roles in controlling telomerase activity; however, little is known about their role in controlling semi-conservative replication, which synthesizes the bulk of telomeric DNA1. Telomere repeats in the fission yeast Schizosaccharomyces pombe are bound by Taz1, a regulator of diverse telomere functions2,3,4. It is generally assumed that telomere-binding proteins impede replication fork progression. Here we show that, on the contrary, Taz1 is crucial for efficient replication fork progression through the telomere. Using two-dimensional gel electrophoresis5, we find that loss of Taz1 leads to stalled replication forks at telomeres and internally placed telomere sequences, regardless of whether the telomeric G-rich strand is replicated by leading- or lagging-strand synthesis. In contrast, the Taz1-interacting protein Rap1 is dispensable for efficient telomeric fork progression. Upon loss of telomerase, taz1Δ telomeres are lost precipitously, suggesting that maintenance of taz1Δ telomere repeats cannot be sustained through semi-conservative replication. As the human telomere proteins TRF1 and TRF2 are Taz1 orthologues, we predict that one or both of the human TRFs may orchestrate fork passage through human telomeres. Stalled forks at dysfunctional human telomeres are likely to accelerate the genomic instability that drives tumorigenesis.

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Figure 1: Efficient semi-conservative replication through telomeres requires Taz1 but not Rap1.
Figure 2: Taz1 is required for efficient replication through internally placed telomere tracts.
Figure 3: Taz1 is required for replication through the telomere/subtelomere boundary.
Figure 4: Differences in the kinetics of telomere attrition and survival mechanism in taz1Δ versus rap1Δ cells after trt1 + deletion.

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References

  1. Teixeira, M. T., Arneric, M., Sperisen, P. & Lingner, J. Telomere length homeostasis is achieved via a switch between telomerase-extendible and -nonextendible states. Cell 117, 323–335 (2004)

    Article  CAS  Google Scholar 

  2. Cooper, J. P., Nimmo, E. R., Allshire, R. C. & Cech, T. R. Regulation of telomere length and function by a Myb-domain protein in fission yeast. Nature 385, 744–747 (1997)

    Article  ADS  CAS  Google Scholar 

  3. Ferreira, M. G. & Cooper, J. P. The fission yeast Taz1 protein protects chromosomes from Ku-dependent end-to-end fusions. Mol. Cell 7, 55–63 (2001)

    Article  CAS  Google Scholar 

  4. Miller, K. M. & Cooper, J. P. The telomere protein Taz1 is required to prevent and repair genomic DNA breaks. Mol. Cell 11, 303–313 (2003)

    Article  CAS  Google Scholar 

  5. Brewer, B. J. & Fangman, W. L. The localization of replication origins on ARS plasmids in S. cerevisiae. Cell 51, 463–471 (1987)

    Article  CAS  Google Scholar 

  6. Nakamura, T. M., Cooper, J. P. & Cech, T. R. Two modes of survival of fission yeast without telomerase. Science 282, 493–496 (1998)

    Article  ADS  CAS  Google Scholar 

  7. Segurado, M., de Luis, A. & Antequera, F. Genome-wide distribution of DNA replication origins at A + T-rich islands in Schizosaccharomyces pombe. EMBO Rep. 4, 1048–1053 (2003)

    Article  CAS  Google Scholar 

  8. Kanoh, J. & Ishikawa, F. spRap1 and spRif1, recruited to telomeres by Taz1, are essential for telomere function in fission yeast. Curr. Biol. 11, 1624–1630 (2001)

    Article  CAS  Google Scholar 

  9. Chikashige, Y. & Hiraoka, Y. Telomere binding of the Rap1 protein is required for meiosis in fission yeast. Curr. Biol. 11, 1618–1623 (2001)

    Article  CAS  Google Scholar 

  10. Miller, K. M., Ferreira, M. G. & Cooper, J. P. Taz1, Rap1 and Rif1 act both interdependently and independently to maintain telomeres. EMBO J. 24, 3128–3185 (2005)

    Article  CAS  Google Scholar 

  11. Dubey, D. D., Zhu, J., Carlson, D. L., Sharma, K. & Huberman, J. A. Three ARS elements contribute to the ura4 replication origin region in the fission yeast, Schizosaccharomyces pombe. EMBO J. 13, 3638–3647 (1994)

    Article  CAS  Google Scholar 

  12. Lambert, S., Watson, A., Sheedy, D. M., Martin, B. & Carr, A. M. Gross chromosomal rearrangements and elevated recombination at an inducible site-specific replication fork barrier. Cell 121, 689–702 (2005)

    Article  CAS  Google Scholar 

  13. Sugawara, N. DNA Sequences at the Telomeres of the Fission Yeast S. pombe. PhD thesis, Harvard Univ. (1988)

    Google Scholar 

  14. Sogo, J. M., Lopes, M. & Foiani, M. Fork reversal and ssDNA accumulation at stalled replication forks owing to checkpoint defects. Science 297, 599–602 (2002)

    Article  ADS  CAS  Google Scholar 

  15. Gasser, R., Koller, T. & Sogo, J. M. The stability of nucleosomes at the replication fork. J. Mol. Biol. 258, 224–239 (1996)

    Article  CAS  Google Scholar 

  16. Beernink, H. T., Miller, K., Deshpande, A., Bucher, P. & Cooper, J. P. Telomere maintenance in fission yeast requires an Est1 ortholog. Curr. Biol. 13, 575–580 (2003)

    Article  CAS  Google Scholar 

  17. Cotta-Ramusino, C. et al. Exo1 processes stalled replication forks and counteracts fork reversal in checkpoint-defective cells. Mol. Cell 17, 153–159 (2005)

    Article  CAS  Google Scholar 

  18. Ahn, J. S., Osman, F. & Whitby, M. C. Replication fork blockage by RTS1 at an ectopic site promotes recombination in fission yeast. EMBO J. 24, 2011–2023 (2005)

    Article  CAS  Google Scholar 

  19. Crabbe, L., Verdun, R. E., Haggblom, C. I. & Karlseder, J. Defective telomere lagging strand synthesis in cells lacking WRN helicase activity. Science 306, 1951–1953 (2004)

    Article  ADS  CAS  Google Scholar 

  20. Ding, H. et al. Regulation of murine telomere length by Rtel: an essential gene encoding a helicase-like protein. Cell 117, 873–886 (2004)

    Article  CAS  Google Scholar 

  21. Ivessa, A. S. et al. The Saccharomyces cerevisiae helicase Rrm3p facilitates replication past nonhistone protein-DNA complexes. Mol. Cell 12, 1525–1536 (2003)

    Article  CAS  Google Scholar 

  22. Ivessa, A. S., Zhou, J. Q., Schulz, V. P., Monson, E. K. & Zakian, V. A. Saccharomyces Rrm3p, a 5′ to 3′ DNA helicase that promotes replication fork progression through telomeric and subtelomeric DNA. Genes Dev. 16, 1383–1396 (2002)

    Article  CAS  Google Scholar 

  23. Makovets, S., Herskowitz, I. & Blackburn, E. H. Anatomy and dynamics of DNA replication fork movement in yeast telomeric regions. Mol. Cell. Biol. 24, 4019–4031 (2004)

    Article  CAS  Google Scholar 

  24. Ohki, R. & Ishikawa, F. Telomere-bound TRF1 and TRF2 stall the replication fork at telomeric repeats. Nucleic Acids Res. 32, 1627–1637 (2004)

    Article  CAS  Google Scholar 

  25. Londono-Vallejo, J. A., Der-Sarkissian, H., Cazes, L., Bacchetti, S. & Reddel, R. R. Alternative lengthening of telomeres is characterized by high rates of telomeric exchange. Cancer Res. 64, 2324–2327 (2004)

    Article  CAS  Google Scholar 

  26. Laud, P. R. et al. Elevated telomere–telomere recombination in WRN-deficient, telomere dysfunctional cells promotes escape from senescence and engagement of the ALT pathway. Genes Dev. 19, 2560–2570 (2005)

    Article  CAS  Google Scholar 

  27. Lustig, A. J. Clues to catastrophic telomere loss in mammals from yeast telomere rapid deletion. Nature Rev. Genet. 4, 916–923 (2003)

    Article  CAS  Google Scholar 

  28. Wang, R. C., Smogorzewska, A. & de Lange, T. Homologous recombination generates T-loop-sized deletions at human telomeres. Cell 119, 355–368 (2004)

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank our laboratory members for discussions and support, and are particularly grateful to A. Hebden for sharing the internal telomere strain, J. Lingner, S. Marcand, Y. Mazor and F. Uhlmann for discussions, and B. Arcangioli, A. Kaykov and C. Heichinger for advice on 2D gel electrophoresis. This work was supported by Cancer Research UK.

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Correspondence to Julia Promisel Cooper.

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This file includes Supplementary Materials and Methods, and Supplementary Figures and Legends 1–3. (PDF 527 kb)

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Miller, K., Rog, O. & Cooper, J. Semi-conservative DNA replication through telomeres requires Taz1. Nature 440, 824–828 (2006). https://doi.org/10.1038/nature04638

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