Skip to main content
PMC home page
Molecular and Cellular Biology logoLink to Molecular and Cellular Biology
. 1996 Apr;16(4):1871–1879. doi: 10.1128/mcb.16.4.1871

A single telomerase RNA is sufficient for the synthesis of variable telomeric DNA repeats in ciliates of the genus Paramecium.

M McCormick-Graham 1, D P Romero 1
PMCID: PMC231174  PMID: 8657163

Abstract

Paramecium telomeric DNA consists largely of a random distribution of TTGGGG and TTTGGG repeats. Given the precise nature of other ciliate telomerases, it has been postulated that there are two distinct types of the Paramecium enzyme, each synthesizing perfect telomeric repeats: one with a template RNA that specifies the addition of TTTGGG and the second dictating the synthesis of TTGGGG repeats. We have cloned and sequenced telomerase RNA genes from Paramecium tetraurelia, P. primaurelia, P. multimicronucleatum, and P. caudatum. Surprisingly, a single gene encodes telomerase RNA in all four species, although an apparently nontranscribed pseudogene is also present in the genome of P. primaurelia. The overall lengths of the telomerase RNAs range between 202 and 209 nucleotides, and they can be folded into a conserved secondary structure similar to that derived for other ciliate RNAs. All Paramecium telomerase RNAs examined include a template specific for the synthesis of TTGGGG telomeric repeats, which has not been posttranscriptionally edited to account for the conventional synthesis of TTTGGG repeats. On the basis of these results, possible mechanisms for the synthesis of variable telomeric repeats by Paramecium telomerase are discussed.

Full Text

The Full Text of this article is available as a PDF (411.9 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Agard D. A., Sedat J. W. Three-dimensional architecture of a polytene nucleus. Nature. 1983 Apr 21;302(5910):676–681. doi: 10.1038/302676a0. [DOI] [PubMed] [Google Scholar]
  2. Autexier C., Greider C. W. Boundary elements of the Tetrahymena telomerase RNA template and alignment domains. Genes Dev. 1995 Sep 15;9(18):2227–2239. doi: 10.1101/gad.9.18.2227. [DOI] [PubMed] [Google Scholar]
  3. Autexier C., Greider C. W. Functional reconstitution of wild-type and mutant Tetrahymena telomerase. Genes Dev. 1994 Mar 1;8(5):563–575. doi: 10.1101/gad.8.5.563. [DOI] [PubMed] [Google Scholar]
  4. Balakrishnan R., Frohlich M., Rahaim P. T., Backman K., Yocum R. R. Appendix. Cloning and sequence of the gene encoding enzyme E-1 from the methionine salvage pathway of Klebsiella oxytoca. J Biol Chem. 1993 Nov 25;268(33):24792–24795. [PubMed] [Google Scholar]
  5. Baroin A., Prat A., Caron F. Telomeric site position heterogeneity in macronuclear DNA of Paramecium primaurelia. Nucleic Acids Res. 1987 Feb 25;15(4):1717–1728. doi: 10.1093/nar/15.4.1717. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Bhattacharyya A., Blackburn E. H. Architecture of telomerase RNA. EMBO J. 1994 Dec 1;13(23):5721–5731. doi: 10.1002/j.1460-2075.1994.tb06910.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Biessmann H., Mason J. M. Genetics and molecular biology of telomeres. Adv Genet. 1992;30:185–249. doi: 10.1016/s0065-2660(08)60321-1. [DOI] [PubMed] [Google Scholar]
  8. Blackburn E. H. Structure and function of telomeres. Nature. 1991 Apr 18;350(6319):569–573. doi: 10.1038/350569a0. [DOI] [PubMed] [Google Scholar]
  9. Blackburn E. H. Telomerases. Annu Rev Biochem. 1992;61:113–129. doi: 10.1146/annurev.bi.61.070192.000553. [DOI] [PubMed] [Google Scholar]
  10. Blasco M. A., Funk W., Villeponteau B., Greider C. W. Functional characterization and developmental regulation of mouse telomerase RNA. Science. 1995 Sep 1;269(5228):1267–1270. doi: 10.1126/science.7544492. [DOI] [PubMed] [Google Scholar]
  11. Chikashige Y., Ding D. Q., Funabiki H., Haraguchi T., Mashiko S., Yanagida M., Hiraoka Y. Telomere-led premeiotic chromosome movement in fission yeast. Science. 1994 Apr 8;264(5156):270–273. doi: 10.1126/science.8146661. [DOI] [PubMed] [Google Scholar]
  12. Cohn M., Blackburn E. H. Telomerase in yeast. Science. 1995 Jul 21;269(5222):396–400. doi: 10.1126/science.7618104. [DOI] [PubMed] [Google Scholar]
  13. Collins K., Greider C. W. Tetrahymena telomerase catalyzes nucleolytic cleavage and nonprocessive elongation. Genes Dev. 1993 Jul;7(7B):1364–1376. doi: 10.1101/gad.7.7b.1364. [DOI] [PubMed] [Google Scholar]
  14. Collins K., Kobayashi R., Greider C. W. Purification of Tetrahymena telomerase and cloning of genes encoding the two protein components of the enzyme. Cell. 1995 Jun 2;81(5):677–686. doi: 10.1016/0092-8674(95)90529-4. [DOI] [PubMed] [Google Scholar]
  15. Fang G., Cech T. R. The beta subunit of Oxytricha telomere-binding protein promotes G-quartet formation by telomeric DNA. Cell. 1993 Sep 10;74(5):875–885. doi: 10.1016/0092-8674(93)90467-5. [DOI] [PubMed] [Google Scholar]
  16. Feng J., Funk W. D., Wang S. S., Weinrich S. L., Avilion A. A., Chiu C. P., Adams R. R., Chang E., Allsopp R. C., Yu J. The RNA component of human telomerase. Science. 1995 Sep 1;269(5228):1236–1241. doi: 10.1126/science.7544491. [DOI] [PubMed] [Google Scholar]
  17. Forney J. D., Blackburn E. H. Developmentally controlled telomere addition in wild-type and mutant paramecia. Mol Cell Biol. 1988 Jan;8(1):251–258. doi: 10.1128/mcb.8.1.251. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Geiduschek E. P., Tocchini-Valentini G. P. Transcription by RNA polymerase III. Annu Rev Biochem. 1988;57:873–914. doi: 10.1146/annurev.bi.57.070188.004301. [DOI] [PubMed] [Google Scholar]
  19. Gilley D., Preer J. R., Jr, Aufderheide K. J., Polisky B. Autonomous replication and addition of telomerelike sequences to DNA microinjected into Paramecium tetraurelia macronuclei. Mol Cell Biol. 1988 Nov;8(11):4765–4772. doi: 10.1128/mcb.8.11.4765. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Giraldo R., Suzuki M., Chapman L., Rhodes D. Promotion of parallel DNA quadruplexes by a yeast telomere binding protein: a circular dichroism study. Proc Natl Acad Sci U S A. 1994 Aug 2;91(16):7658–7662. doi: 10.1073/pnas.91.16.7658. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Greider C. W., Blackburn E. H. A telomeric sequence in the RNA of Tetrahymena telomerase required for telomere repeat synthesis. Nature. 1989 Jan 26;337(6205):331–337. doi: 10.1038/337331a0. [DOI] [PubMed] [Google Scholar]
  22. Greider C. W., Blackburn E. H. Identification of a specific telomere terminal transferase activity in Tetrahymena extracts. Cell. 1985 Dec;43(2 Pt 1):405–413. doi: 10.1016/0092-8674(85)90170-9. [DOI] [PubMed] [Google Scholar]
  23. Greider C. W., Blackburn E. H. The telomere terminal transferase of Tetrahymena is a ribonucleoprotein enzyme with two kinds of primer specificity. Cell. 1987 Dec 24;51(6):887–898. doi: 10.1016/0092-8674(87)90576-9. [DOI] [PubMed] [Google Scholar]
  24. Guild N., Gayle M., Sweeney R., Hollingsworth T., Modeer T., Gold L. Transcriptional activation of bacteriophage T4 middle promoters by the motA protein. J Mol Biol. 1988 Jan 20;199(2):241–258. doi: 10.1016/0022-2836(88)90311-7. [DOI] [PubMed] [Google Scholar]
  25. Haynes W. J., Ling K. Y., Saimi Y., Kung C. Induction of antibiotic resistance in Paramecium tetraurelia by the bacterial gene APH-3'-II. J Eukaryot Microbiol. 1995 Jan-Feb;42(1):83–91. doi: 10.1111/j.1550-7408.1995.tb01545.x. [DOI] [PubMed] [Google Scholar]
  26. Henderson E. R., Blackburn E. H. An overhanging 3' terminus is a conserved feature of telomeres. Mol Cell Biol. 1989 Jan;9(1):345–348. doi: 10.1128/mcb.9.1.345. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Henderson E., Hardin C. C., Walk S. K., Tinoco I., Jr, Blackburn E. H. Telomeric DNA oligonucleotides form novel intramolecular structures containing guanine-guanine base pairs. Cell. 1987 Dec 24;51(6):899–908. doi: 10.1016/0092-8674(87)90577-0. [DOI] [PubMed] [Google Scholar]
  28. Hochstrasser M., Mathog D., Gruenbaum Y., Saumweber H., Sedat J. W. Spatial organization of chromosomes in the salivary gland nuclei of Drosophila melanogaster. J Cell Biol. 1986 Jan;102(1):112–123. doi: 10.1083/jcb.102.1.112. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Klein F., Laroche T., Cardenas M. E., Hofmann J. F., Schweizer D., Gasser S. M. Localization of RAP1 and topoisomerase II in nuclei and meiotic chromosomes of yeast. J Cell Biol. 1992 Jun;117(5):935–948. doi: 10.1083/jcb.117.5.935. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Kramer K. M., Haber J. E. New telomeres in yeast are initiated with a highly selected subset of TG1-3 repeats. Genes Dev. 1993 Dec;7(12A):2345–2356. doi: 10.1101/gad.7.12a.2345. [DOI] [PubMed] [Google Scholar]
  31. Labeit S., Lehrach H., Goody R. S. DNA sequencing using alpha-thiodeoxynucleotides. Methods Enzymol. 1987;155:166–177. doi: 10.1016/0076-6879(87)55015-7. [DOI] [PubMed] [Google Scholar]
  32. Lin J. J., Zakian V. A. An in vitro assay for Saccharomyces telomerase requires EST1. Cell. 1995 Jun 30;81(7):1127–1135. doi: 10.1016/s0092-8674(05)80017-0. [DOI] [PubMed] [Google Scholar]
  33. Lingner J., Hendrick L. L., Cech T. R. Telomerase RNAs of different ciliates have a common secondary structure and a permuted template. Genes Dev. 1994 Aug 15;8(16):1984–1998. doi: 10.1101/gad.8.16.1984. [DOI] [PubMed] [Google Scholar]
  34. Lonergan K. M., Gray M. W. Editing of transfer RNAs in Acanthamoeba castellanii mitochondria. Science. 1993 Feb 5;259(5096):812–816. doi: 10.1126/science.8430334. [DOI] [PubMed] [Google Scholar]
  35. Mantell L. L., Greider C. W. Telomerase activity in germline and embryonic cells of Xenopus. EMBO J. 1994 Jul 1;13(13):3211–3217. doi: 10.1002/j.1460-2075.1994.tb06620.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. McCormick-Graham M., Romero D. P. Ciliate telomerase RNA structural features. Nucleic Acids Res. 1995 Apr 11;23(7):1091–1097. doi: 10.1093/nar/23.7.1091. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. McEachern M. J., Blackburn E. H. A conserved sequence motif within the exceptionally diverse telomeric sequences of budding yeasts. Proc Natl Acad Sci U S A. 1994 Apr 12;91(8):3453–3457. doi: 10.1073/pnas.91.8.3453. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. McEachern M. J., Blackburn E. H. Runaway telomere elongation caused by telomerase RNA gene mutations. Nature. 1995 Aug 3;376(6539):403–409. doi: 10.1038/376403a0. [DOI] [PubMed] [Google Scholar]
  39. McEachern M. J., Hicks J. B. Unusually large telomeric repeats in the yeast Candida albicans. Mol Cell Biol. 1993 Jan;13(1):551–560. doi: 10.1128/mcb.13.1.551. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Melek M., Davis B. T., Shippen D. E. Oligonucleotides complementary to the Oxytricha nova telomerase RNA delineate the template domain and uncover a novel mode of primer utilization. Mol Cell Biol. 1994 Dec;14(12):7827–7838. doi: 10.1128/mcb.14.12.7827. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Morin G. B. The human telomere terminal transferase enzyme is a ribonucleoprotein that synthesizes TTAGGG repeats. Cell. 1989 Nov 3;59(3):521–529. doi: 10.1016/0092-8674(89)90035-4. [DOI] [PubMed] [Google Scholar]
  42. Novo F. J., Kruszewski A., MacDermot K. D., Goldspink G., Górecki D. C. Editing of human alpha-galactosidase RNA resulting in a pyrimidine to purine conversion. Nucleic Acids Res. 1995 Jul 25;23(14):2636–2640. doi: 10.1093/nar/23.14.2636. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Nutt S. L., Hoo K. H., Rampersad V., Deverill R. M., Elliott C. E., Fletcher E. J., Adams S. L., Korczak B., Foldes R. L., Kamboj R. K. Molecular characterization of the human EAA5 (GluR7) receptor: a high-affinity kainate receptor with novel potential RNA editing sites. Receptors Channels. 1994;2(4):315–326. [PubMed] [Google Scholar]
  44. Orum H., Nielsen H., Engberg J. Structural organization of the genes encoding the small nuclear RNAs U1 to U6 of Tetrahymena thermophila is very similar to that of plant small nuclear RNA genes. J Mol Biol. 1992 Sep 5;227(1):114–121. doi: 10.1016/0022-2836(92)90686-e. [DOI] [PubMed] [Google Scholar]
  45. Pace N. R., Smith D. K., Olsen G. J., James B. D. Phylogenetic comparative analysis and the secondary structure of ribonuclease P RNA--a review. Gene. 1989 Oct 15;82(1):65–75. doi: 10.1016/0378-1119(89)90031-0. [DOI] [PubMed] [Google Scholar]
  46. Prowse K. R., Avilion A. A., Greider C. W. Identification of a nonprocessive telomerase activity from mouse cells. Proc Natl Acad Sci U S A. 1993 Feb 15;90(4):1493–1497. doi: 10.1073/pnas.90.4.1493. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Romero D. P., Blackburn E. H. A conserved secondary structure for telomerase RNA. Cell. 1991 Oct 18;67(2):343–353. doi: 10.1016/0092-8674(91)90186-3. [DOI] [PubMed] [Google Scholar]
  48. Romero D. P., Blackburn E. H. Circular rDNA replicons persist in Tetrahymena thermophila transformants synthesizing GGGGTC telomeric repeats. J Eukaryot Microbiol. 1995 Jan-Feb;42(1):32–43. doi: 10.1111/j.1550-7408.1995.tb01537.x. [DOI] [PubMed] [Google Scholar]
  49. Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Sheng H., Hou Z., Schierer T., Dobbs D. L., Henderson E. Identification and characterization of a putative telomere end-binding protein from Tetrahymena thermophila. Mol Cell Biol. 1995 Mar;15(3):1144–1153. doi: 10.1128/mcb.15.3.1144. [DOI] [PMC free article] [PubMed] [Google Scholar]
  51. Shippen-Lentz D., Blackburn E. H. Functional evidence for an RNA template in telomerase. Science. 1990 Feb 2;247(4942):546–552. doi: 10.1126/science.1689074. [DOI] [PubMed] [Google Scholar]
  52. Shippen-Lentz D., Blackburn E. H. Telomere terminal transferase activity from Euplotes crassus adds large numbers of TTTTGGGG repeats onto telomeric primers. Mol Cell Biol. 1989 Jun;9(6):2761–2764. doi: 10.1128/mcb.9.6.2761. [DOI] [PMC free article] [PubMed] [Google Scholar]
  53. Singer M. S., Gottschling D. E. TLC1: template RNA component of Saccharomyces cerevisiae telomerase. Science. 1994 Oct 21;266(5184):404–409. doi: 10.1126/science.7545955. [DOI] [PubMed] [Google Scholar]
  54. Sogin M. L., Ingold A., Karlok M., Nielsen H., Engberg J. Phylogenetic evidence for the acquisition of ribosomal RNA introns subsequent to the divergence of some of the major Tetrahymena groups. EMBO J. 1986 Dec 20;5(13):3625–3630. doi: 10.1002/j.1460-2075.1986.tb04691.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Strohman R. C., Moss P. S., Micou-Eastwood J., Spector D., Przybyla A., Paterson B. Messenger RNA for myosin polypeptides: isolation from single myogenic cell cultures. Cell. 1977 Feb;10(2):265–273. doi: 10.1016/0092-8674(77)90220-3. [DOI] [PubMed] [Google Scholar]
  56. Vieira J., Messing J. Production of single-stranded plasmid DNA. Methods Enzymol. 1987;153:3–11. doi: 10.1016/0076-6879(87)53044-0. [DOI] [PubMed] [Google Scholar]
  57. Yu G. L., Blackburn E. H. Amplification of tandemly repeated origin control sequences confers a replication advantage on rDNA replicons in Tetrahymena thermophila. Mol Cell Biol. 1990 May;10(5):2070–2080. doi: 10.1128/mcb.10.5.2070. [DOI] [PMC free article] [PubMed] [Google Scholar]
  58. Yu G. L., Blackburn E. H. Developmentally programmed healing of chromosomes by telomerase in Tetrahymena. Cell. 1991 Nov 15;67(4):823–832. doi: 10.1016/0092-8674(91)90077-c. [DOI] [PubMed] [Google Scholar]
  59. Yu G. L., Bradley J. D., Attardi L. D., Blackburn E. H. In vivo alteration of telomere sequences and senescence caused by mutated Tetrahymena telomerase RNAs. Nature. 1990 Mar 8;344(6262):126–132. doi: 10.1038/344126a0. [DOI] [PubMed] [Google Scholar]
  60. Zahler A. M., Prescott D. M. Telomere terminal transferase activity in the hypotrichous ciliate Oxytricha nova and a model for replication of the ends of linear DNA molecules. Nucleic Acids Res. 1988 Jul 25;16(14B):6953–6972. doi: 10.1093/nar/16.14.6953. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Zakian V. A. Structure and function of telomeres. Annu Rev Genet. 1989;23:579–604. doi: 10.1146/annurev.ge.23.120189.003051. [DOI] [PubMed] [Google Scholar]
  62. Zaug A. J., Cech T. R. Analysis of the structure of Tetrahymena nuclear RNAs in vivo: telomerase RNA, the self-splicing rRNA intron, and U2 snRNA. RNA. 1995 Jun;1(4):363–374. [PMC free article] [PubMed] [Google Scholar]
  63. ten Dam E., van Belkum A., Pleij K. A conserved pseudoknot in telomerase RNA. Nucleic Acids Res. 1991 Dec 25;19(24):6951–6951. doi: 10.1093/nar/19.24.6951. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Molecular and Cellular Biology are provided here courtesy of Taylor & Francis

RESOURCES