Telomere-Binding Proteins of Ciliated Protozoa

  • C. M. Price
Part of the Nucleic Acids and Molecular Biology book series (NUCLEIC, volume 9)

Abstract

A great deal of our current knowledge about telomere structure and function has come from studies performed with ciliated protozoa. The reason that studies of ciliate telomeres have been so productive stems from the unusual genomic organization of these organisms. All ciliates have two functionally and structurally distinct nuclei: the germline micronucleus and the vegetative macronucleus. Although the micronucleus contains relatively few large chromosomes, the macronucleus contains thousands or millions of separate DNA molecules that have telomeres on each end (Blackburn 1986; Klobutcher and Prescott 1986). For example, macronuclei from the holotrichous ciliate Tetrahymena contain over 1 x 104 DNA molecules (2 x 104 telomeres) while macronuclei from the hypotrichous ciliates Euplotes and Oxytricha contain >2 x 107 DNA molecules (>4 x 107 telomeres). This abundance of macronuclear telomeres has greatly facilitated the characterization of telomere structure and isolation of telomere-binding proteins.

Keywords

Filtration Adduct Polypeptide Trypsin Gall 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Biessmann H, Mason JM (1992) Genetics and molecular biology of telomeres. Adv Genet 30:209–238Google Scholar
  2. Blackburn EH (1986) Telomeres. In: Gall J (ed) The molecular biology of ciliated protozoa. Academic Press, OrlandoGoogle Scholar
  3. Blackburn EH, Chiou SA (1981) Non-nucleosomal packaging of a tandemly repeated DNA sequence at termini of extrachromosomal DNA coding for rRNA in Tetrahymena. Proc Natl Acad Sci USA 78:2263–2267PubMedCrossRefGoogle Scholar
  4. Budarf ML, Blackburn EH (1986) Chromatin structure of the telomeric region and 3′-nontranscribed spacer of Tetrahymena ribosomal RNA genes. J Biol Chem 261:363–369PubMedGoogle Scholar
  5. Cardenas ME, Bianchi A, deLange T (1993) A Xenopus egg factor with DNA-binding properties characteristic of terminus-specific telomeric proteins. Genes Dev 7:883–898PubMedCrossRefGoogle Scholar
  6. Fang G, Cech T (1991) Molecular cloning of telomere-binding protein genes from Stylonychia mytilis. Nucleic Acids Res 19:5515–5518.PubMedCrossRefGoogle Scholar
  7. Fang G, Cech TR (1993a) Oxytricha telomere-binding protein: DNA-dependent dimerization of the alpha and beta subunits. Proc Natl Acad Sci USA 90:6057–6060CrossRefGoogle Scholar
  8. Fang G, Cech TR (1993b) The β subunit of Oxytricha telomere-binding protein promotes G-quartet formation by telomeric DNA. Cell 74:875–885PubMedCrossRefGoogle Scholar
  9. Fang G, Cech TR (1993c) Characterization of a G-quartet formation reaction promoted by the β-subunit of the Oxytricha telomere-binding protein. Biochemistry 32:11646–11657PubMedCrossRefGoogle Scholar
  10. Fang G, Gray JT, Cech TR (1993) Oxytricha telomere-binding protein: separable DNA-binding and dimerisation domains of the alpha subunit. Genes Dev 7:870–882PubMedCrossRefGoogle Scholar
  11. Gottschling DE, Cech TR (1984) Chromatin structure of the molecular ends of Oxytricha macronuclear DNA: phased nucleosomes and a telomeric complex. Cell 38:501–510PubMedCrossRefGoogle Scholar
  12. Gottschling DE, Zakian VA (1986) Telomere proteins: specific recognition and protection of the natural termini of Oxytricha macronuclear DNA. Cell 47:195–205PubMedCrossRefGoogle Scholar
  13. Gray JT, Celander DW, Price CM, Cech TR (1991) Cloning and expression of genes for the Oxytricha telomere-binding protein: specific subunit interactions in the telomeric complex. Cell 67:807–814PubMedCrossRefGoogle Scholar
  14. Hicke B, Celander D, Macdonald G, Price C, Cech T (1990) Two versions of the gene encoding the 41 kilodalton subunit of the telomere binding protein of Oxytricha nova. Proc Natl Acad Sci USA 87:1481–1485PubMedCrossRefGoogle Scholar
  15. Hicke BJ, Willis MC, Koch TH, Cech TR (1994) Telomeric protein-DNA contacts identified by photo-cross-linking using 5′ bromodeoxyuridine. Biochemistry 33:3364–3373PubMedCrossRefGoogle Scholar
  16. Klobutcher LA, Prescott DM (1986) The special case of the hypotrichs. In: Gall JG (ed) Molecular biology of ciliated protozoa. Academic Press, New YorkGoogle Scholar
  17. Price CM (1990) Telomere structure in Euplotes crass us: characterization of DNA-protein interactions and isolation of a telomere-binding protein. Mol Cell Biol 10:3421–3431PubMedGoogle Scholar
  18. Price CM, Cech TR (1987) Telomeric DNA-protein interactions of Oxytricha macronuclear DNA. Genes Dev 1:783–793PubMedCrossRefGoogle Scholar
  19. Price CM, Cech TR (1989) Properties of the telomeric DNA-binding protein from Oxytricha nova. Biochemistry 28:769–774PubMedCrossRefGoogle Scholar
  20. Price C, Skopp R, Krueger J, Williams D (1992) DNA recognition and binding by the Euplotes telomere protein. Biochemistry 31:10835–10843PubMedCrossRefGoogle Scholar
  21. Raghuraman MK, Cech TR (1990) Effect of monovalent cation-induced telomeric DNA structure on the binding of Oxytricha telomeric protein. Nucleic Acids Res 18:4543–4551PubMedCrossRefGoogle Scholar
  22. Raghuraman MK, Dun CJ, Hicke BJ, Cech TR (1989) Oxytricha telomeric nucleoprotein complexes reconstituted with synthetic DNA. Nucleic Acids Res 17:4235–4253PubMedCrossRefGoogle Scholar
  23. Shippen DE, Blackburn EH, Price CM (1994) DNA bound by the Oxytricha telomere protein is accessible to telomerase and other DNA polymerases. Proc Natl Acad Sci USA 91:405–409PubMedCrossRefGoogle Scholar
  24. Sundquist WJ (1991) The structures of telomeric DNA. In: Eckstein F, Lilley DMJ (eds) Nucleic Acids and Molecular Biology, vol 5. Springer, Berlin Heidelberg New York, pp 1–24CrossRefGoogle Scholar
  25. Wang W-L, Skopp R, Scofield M, Price C (1992) Euplotes crassus has genes encoding telomere-binding proteins and telomere-binding protein homologs. Nucleic Acids Res 20:6621–6629PubMedCrossRefGoogle Scholar
  26. Williamson JR, Raghuraman MK, Cech TR (1989) Monovalent cation-induced structure of telomeric DNA: the G-quartet model. Cell 59:871–880PubMedCrossRefGoogle Scholar
  27. Wright JH, Gottschling DE, Zakian VA (1993) Saccharomyces telomeres assume a nonnucleosomal chromatin structure. Genes Dev 6:197–210CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1995

Authors and Affiliations

  • C. M. Price
    • 1
  1. 1.Department of ChemistryUniversity of NebraskaLincolnUSA

Personalised recommendations