Abstract
Activation of the chromosome end-replicating enzyme telomerase can greatly extend the lifespan of normal human cells1 and is associated with most human cancers2. In all eukaryotes examined, telomerase has an RNA subunit3, a conserved reverse transcriptase subunit4 and additional proteins5,6, but little is known about the assembly of these components. Here we show that the Saccharomyces cerevisiae telomerase RNA7 has a 5′-2,2,7-trimethylguanosine (TMG) cap and a binding site for the Sm proteins, both hallmarks of small nuclear ribonucleoprotein particles (snRNPs) that are involved in nuclear messenger RNA splicing8,9. Immunoprecipitation of telomerase from yeast extracts shows that Sm proteins are assembled on the RNA and that most or all of the telomerase activity is associated with the Sm-containing complex. These data support a model in which telomerase RNA is transcribed by RNA polymerase II (ref. 10) and 7-methylguanosine-capped, binds the seven Sm proteins, becomes TMG-capped and picks up the other protein subunits. We conclude that the functions of snRNPs assembled by this pathway are not restricted to RNA processing, but also include chromosome telomere replication.
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References
Bodnar,A. G. et al. Extension of life-span by introduction of telomerase into normal human cells. Science 279, 349–352 (1998).
Kim,N. W. et al. Specific association of human telomerase activity with immortal cells and cancer. Science 266, 2011–2103 (1994).
Greider,C. W. & Blackburn,E. H. A telomeric sequence in the RNA of Tetrahymena telomerase required for telomere repeat synthesis. Nature 337, 331–337 (1989).
Lingner,J. et al. Reverse transcriptase motifs in the catalytic subunit of telomerase. Science 276, 561–567 (1997).
Bryan,T. M. & Cech,T. R. Telomerase and the maintenance of chromosome ends. Curr. Opin. Cell Biol. 11, 318–324 (1999).
Nugent,C. I. & Lundblad,V. The telomerase reverse transcriptase: components and regulation. Genes Dev. 12, 1073–1085 (1998).
Singer,M. S. & Gottschling,D. E. TLC1: template RNA component of Saccharomyces cerevisiae telomerase. Science 266, 404–409 (1994).
Lührmann,R., Kastner,B. & Bach,M. Structure of spliceosomal snRNPs and their role in pre-mRNA splicing. Biochim. Biophys. Acta 1087, 265–292 (1990).
Mattaj,I. W. Cap trimethylation of U snRNA is cytoplasmic and dependent on U snRNP protein binding. Cell 46, 905–911 (1986).
Chapon,C., Cech,T. R. & Zaug,A. J. Polyadenylation of telomerase RNA in budding yeast. RNA 3, 1337–1351 (1997).
Yu, Y.-T., Scharl,E. C., Smith,C. M. & Steitz,J. A. in The RNA World (eds Gesteland, R. F., Cech, T. R. & Atkins, J. F.) 487–524 (Cold Spring Harbor Lab. Press, Cold Spring Harbor, New York, 1999).
Jones,M. H. & Guthrie,C. Unexpected flexibility in an evolutionarily conserved protein–RNA interaction: genetic analysis of the Sm binding site. EMBO J. 9, 2555–2561 (1990).
Lendvay,T. S., Morris,D. K., Sah,J., Balasubramanian,B. & Lundblad,V. Senescence mutants of Saccharomyces cerevisiae with a defect in telomere replication identify three additional EST genes. Genetics 144, 1399–1412 (1996).
Roy,J., Zheng,B., Rymond,B. C. & Woolford, J. L. Jr Structurally related but functionally distinct yeast Sm D core small nuclear ribonucleoprotein particle proteins. Mol. Cell. Biol. 15, 445–455 (1995).
Pettersson,I., Hinterberger,M., Mimori,T., Gottlieb,E. & Steitz,J. A. The structure of mammalian small nuclear ribonucleoproteins: identification of multiple protein components reactive with anti-(U1)RNP and anti-Sm autoantibodies. J. Biol. Chem. 259, 5907–5914 (1984).
Neubauer G. et al. Identification of the proteins of the yeast U1 small nuclear ribonucleoprotein complex by mass spectrometry. Proc. Natl Acad. Sci. USA 94, 385–390 (1997).
Cohn,M. & Blackburn,E. H. Telomerase in yeast. Science 269, 396–400 (1995).
Prescott,J. & Blackburn,E. H. Telomerase RNA mutations in Saccharomyces cerevisiae alter telomerase action and reveal nonprocessivity in vivo and in vitro. Genes Dev. 11, 528–540 (1997).
Seipelt,R. L., Zhang,B., Asuru,A. & Rymond,B. U1 snRNA is cleaved by RNase III and processed through an Sm site-dependent pathway. Nucleic Acids Res. 27, 587–595 (1999).
Elela,S. A. & Ares, M. Jr Depletion of yeast RNase III blocks correct U2 3′ end formation and results in polyadenylated but functional U2 snRNA. EMBO J. 17, 3738–3746 (1998).
Kambach,C. et al. Crystal structures of two Sm protein complexes and their implications for the assembly of the spliceosomal snRNPs. Cell 96, 375–387 (1999).
Mitchell,J. R., Cheng,J. & Collins,K. A box H/ACA small nucleolar RNA-like domain at the human telomerase RNA 3′ end. Mol. Cell. Biol. 19, 567–576 (1999).
Mattaj,I. W. in Structure and Function of Major and Minor Small Nuclear Ribonucleoprotein Particles (ed. Birnstiel, M. L.) 100–114 (Springer, Berlin, 1988).
Virta-Pearlman,G., Morris,D. K. & Lundblad,V. Est1 has the properties of a single-stranded telomere end-binding protein. Genes Dev. 10, 3094–3104 (1996).
Rose,M. D., Winston,F. & Hieter,P. Methods in Yeast Genetics. A Laboratory Manual 177–186 (Cold Spring Harbor Lab. Press, Cold Spring Harbor, New York, 1990).
Schiestl,R. H. & Gietz,R. D. High efficiency transformation of intact yeast cells using single stranded nucleic acids as a carrier. Curr. Genet. 16, 339–346 (1989).
Scherer,S. & Davis,R. W. Replacement of chromosome segments with altered DNA sequences constructed in vitro. Proc. Natl Acad. Sci. USA 76, 4951–4955 (1979).
Ey,P. L., Prowse,S. J. & Jenkin,C. R. Isolation of pure IgG1, IgG2a and IgG2b immunoglobins from mouse serum using Protein A-sepharose. Immunochemistry 15, 429–436 (1978).
Acknowledgements
We thank K. Friedman, D. Gottschling, and B. Rymond for yeast plasmids and strains; R. Weilbaecher and V. Lundblad for their telomerase activity assay protocol; and the Cech lab and J. Goodrich for discussions. This work was supported by grants from the NIH to T.R.C. and S.L.W. T.R.C. and S.L.W. are investigators of the Howard Hughes Medical Institute.
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Seto, A., Zaug, A., Sobel, S. et al. Saccharomyces cerevisiae telomerase is an Sm small nuclear ribonucleoprotein particle. Nature 401, 177–180 (1999). https://doi.org/10.1038/43694
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DOI: https://doi.org/10.1038/43694