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. 1993 Jan;13(1):144–154. doi: 10.1128/mcb.13.1.144

RNA B is the major nucleolar trimethylguanosine-capped small nuclear RNA associated with fibrillarin and pre-rRNAs in Trypanosoma brucei.

T Hartshorne 1, N Agabian 1
PMCID: PMC358894  PMID: 8417321

Abstract

RNA B is one of three abundant trimethylguanosine-capped U small nuclear RNAs (snRNAs) of Trypanosoma brucei which is not strongly identified with other U snRNAs by sequence homology. We show here that RNA B is a highly diverged U3 snRNA homolog likely involved in pre-rRNA processing. Sequence identity between RNA B and U3 snRNAs is limited; only two of four boxes of homology conserved between U3 snRNAs are obvious in RNA B. These are the box A homology, specific for U3 snRNAs, and the box C homology, common to nucleolar snRNAs and required for association with the nucleolar protein, fibrillarin. A 35-kDa T. brucei fibrillarin homolog was identified by using an anti-Physarum fibrillarin monoclonal antibody. RNA B and fibrillarin were localized in nucleolar fractions of the nucleus which contained pre-rRNAs and did not contain nucleoplasmic snRNAs. Fibrillarin and RNA B were precipitated by scleroderma patient serum S4, which reacts with fibrillarins from diverse organisms; RNA B was the only trimethylguanosine-capped RNA precipitated. Furthermore, RNA B sedimented with pre-rRNAs in nondenaturing sucrose gradients, similarly to U3 and other nucleolar snRNAs, suggesting that RNA B is hydrogen bonded to rRNA intermediates and might be involved in their processing.

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Selected References

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

  1. Agabian N. Trans splicing of nuclear pre-mRNAs. Cell. 1990 Jun 29;61(7):1157–1160. doi: 10.1016/0092-8674(90)90674-4. [DOI] [PubMed] [Google Scholar]
  2. Aris J. P., Blobel G. cDNA cloning and sequencing of human fibrillarin, a conserved nucleolar protein recognized by autoimmune antisera. Proc Natl Acad Sci U S A. 1991 Feb 1;88(3):931–935. doi: 10.1073/pnas.88.3.931. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Baserga S. J., Yang X. D., Steitz J. A. An intact Box C sequence in the U3 snRNA is required for binding of fibrillarin, the protein common to the major family of nucleolar snRNPs. EMBO J. 1991 Sep;10(9):2645–2651. doi: 10.1002/j.1460-2075.1991.tb07807.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Beltrame M., Tollervey D. Identification and functional analysis of two U3 binding sites on yeast pre-ribosomal RNA. EMBO J. 1992 Apr;11(4):1531–1542. doi: 10.1002/j.1460-2075.1992.tb05198.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Campbell D. A., Kubo K., Clark C. G., Boothroyd J. C. Precise identification of cleavage sites involved in the unusual processing of trypanosome ribosomal RNA. J Mol Biol. 1987 Jul 5;196(1):113–124. doi: 10.1016/0022-2836(87)90514-6. [DOI] [PubMed] [Google Scholar]
  6. Christensen M. E., Moloo J., Swischuk J. L., Schelling M. E. Characterization of the nucleolar protein, B-36, using monoclonal antibodies. Exp Cell Res. 1986 Sep;166(1):77–93. doi: 10.1016/0014-4827(86)90509-4. [DOI] [PubMed] [Google Scholar]
  7. Craig N., Kass S., Sollner-Webb B. Sequence organization and RNA structural motifs directing the mouse primary rRNA-processing event. Mol Cell Biol. 1991 Jan;11(1):458–467. doi: 10.1128/mcb.11.1.458. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Epstein P., Reddy R., Busch H. Multiple states of U3 RNA in Novikoff hepatoma nucleoli. Biochemistry. 1984 Nov 6;23(23):5421–5425. doi: 10.1021/bi00318a007. [DOI] [PubMed] [Google Scholar]
  9. Guiltinan M. J., Schelling M. E., Ehtesham N. Z., Thomas J. C., Christensen M. E. The nucleolar RNA-binding protein B-36 is highly conserved among plants. Eur J Cell Biol. 1988 Aug;46(3):547–553. [PubMed] [Google Scholar]
  10. Henríquez R., Blobel G., Aris J. P. Isolation and sequencing of NOP1. A yeast gene encoding a nucleolar protein homologous to a human autoimmune antigen. J Biol Chem. 1990 Feb 5;265(4):2209–2215. [PubMed] [Google Scholar]
  11. Hernandez-Verdun D. The nucleolus today. J Cell Sci. 1991 Jul;99(Pt 3):465–471. doi: 10.1242/jcs.99.3.465. [DOI] [PubMed] [Google Scholar]
  12. Hughes J. M., Ares M., Jr Depletion of U3 small nucleolar RNA inhibits cleavage in the 5' external transcribed spacer of yeast pre-ribosomal RNA and impairs formation of 18S ribosomal RNA. EMBO J. 1991 Dec;10(13):4231–4239. doi: 10.1002/j.1460-2075.1991.tb05001.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hughes J. M., Konings D. A., Cesareni G. The yeast homologue of U3 snRNA. EMBO J. 1987 Jul;6(7):2145–2155. doi: 10.1002/j.1460-2075.1987.tb02482.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Jansen R. P., Hurt E. C., Kern H., Lehtonen H., Carmo-Fonseca M., Lapeyre B., Tollervey D. Evolutionary conservation of the human nucleolar protein fibrillarin and its functional expression in yeast. J Cell Biol. 1991 May;113(4):715–729. doi: 10.1083/jcb.113.4.715. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Jeppesen C., Stebbins-Boaz B., Gerbi S. A. Nucleotide sequence determination and secondary structure of Xenopus U3 snRNA. Nucleic Acids Res. 1988 Mar 25;16(5):2127–2148. doi: 10.1093/nar/16.5.2127. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Kass S., Craig N., Sollner-Webb B. Primary processing of mammalian rRNA involves two adjacent cleavages and is not species specific. Mol Cell Biol. 1987 Aug;7(8):2891–2898. doi: 10.1128/mcb.7.8.2891. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Kass S., Tyc K., Steitz J. A., Sollner-Webb B. The U3 small nucleolar ribonucleoprotein functions in the first step of preribosomal RNA processing. Cell. 1990 Mar 23;60(6):897–908. doi: 10.1016/0092-8674(90)90338-f. [DOI] [PubMed] [Google Scholar]
  18. Kiss T., Solymosy F. Molecular analysis of a U3 RNA gene locus in tomato: transcription signals, the coding region, expression in transgenic tobacco plants and tandemly repeated pseudogenes. Nucleic Acids Res. 1990 Apr 25;18(8):1941–1949. doi: 10.1093/nar/18.8.1941. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Laird P. W. Trans splicing in trypanosomes--archaism or adaptation? Trends Genet. 1989 Jul;5(7):204–208. doi: 10.1016/0168-9525(89)90082-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Lapeyre B., Mariottini P., Mathieu C., Ferrer P., Amaldi F., Amalric F., Caizergues-Ferrer M. Molecular cloning of Xenopus fibrillarin, a conserved U3 small nuclear ribonucleoprotein recognized by antisera from humans with autoimmune disease. Mol Cell Biol. 1990 Jan;10(1):430–434. doi: 10.1128/mcb.10.1.430. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Li H. D., Zagorski J., Fournier M. J. Depletion of U14 small nuclear RNA (snR128) disrupts production of 18S rRNA in Saccharomyces cerevisiae. Mol Cell Biol. 1990 Mar;10(3):1145–1152. doi: 10.1128/mcb.10.3.1145. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Maser R. L., Calvet J. P. U3 small nuclear RNA can be psoralen-cross-linked in vivo to the 5' external transcribed spacer of pre-ribosomal-RNA. Proc Natl Acad Sci U S A. 1989 Sep;86(17):6523–6527. doi: 10.1073/pnas.86.17.6523. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Mottram J., Perry K. L., Lizardi P. M., Lührmann R., Agabian N., Nelson R. G. Isolation and sequence of four small nuclear U RNA genes of Trypanosoma brucei subsp. brucei: identification of the U2, U4, and U6 RNA analogs. Mol Cell Biol. 1989 Mar;9(3):1212–1223. doi: 10.1128/mcb.9.3.1212. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Ochs R. L., Lischwe M. A., Spohn W. H., Busch H. Fibrillarin: a new protein of the nucleolus identified by autoimmune sera. Biol Cell. 1985;54(2):123–133. doi: 10.1111/j.1768-322x.1985.tb00387.x. [DOI] [PubMed] [Google Scholar]
  25. Parker K. A., Bruzik J. P., Steitz J. A. An in vitro interaction between the human U3 snRNP and 28S rRNA sequences near the alpha-sarcin site. Nucleic Acids Res. 1988 Nov 25;16(22):10493–10509. doi: 10.1093/nar/16.22.10493. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Parker K. A., Steitz J. A. Structural analysis of the human U3 ribonucleoprotein particle reveal a conserved sequence available for base pairing with pre-rRNA. Mol Cell Biol. 1987 Aug;7(8):2899–2913. doi: 10.1128/mcb.7.8.2899. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Porter G. L., Brennwald P. J., Holm K. A., Wise J. A. The sequence of U3 from Schizosaccharomyces pombe suggests structural divergence of this snRNA between metazoans and unicellular eukaryotes. Nucleic Acids Res. 1988 Nov 11;16(21):10131–10152. doi: 10.1093/nar/16.21.10131. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Prestayko A. W., Tonato M., Busch H. Low molecular weight RNA associated with 28 s nucleolar RNA. J Mol Biol. 1970 Feb 14;47(3):505–515. doi: 10.1016/0022-2836(70)90318-9. [DOI] [PubMed] [Google Scholar]
  29. Puvion-Dutilleul F., Mazan S., Nicoloso M., Christensen M. E., Bachellerie J. P. Localization of U3 RNA molecules in nucleoli of HeLa and mouse 3T3 cells by high resolution in situ hybridization. Eur J Cell Biol. 1991 Dec;56(2):178–186. [PubMed] [Google Scholar]
  30. Reddy R., Li W. Y., Henning D., Choi Y. C., Nohga K., Busch H. Characterization and subcellular localization of 7-8 S RNAs of Novikoff hepatoma. J Biol Chem. 1981 Aug 25;256(16):8452–8457. [PubMed] [Google Scholar]
  31. Reimer G., Pollard K. M., Penning C. A., Ochs R. L., Lischwe M. A., Busch H., Tan E. M. Monoclonal autoantibody from a (New Zealand black x New Zealand white)F1 mouse and some human scleroderma sera target an Mr 34,000 nucleolar protein of the U3 RNP particle. Arthritis Rheum. 1987 Jul;30(7):793–800. doi: 10.1002/art.1780300709. [DOI] [PubMed] [Google Scholar]
  32. Reuter R., Tessars G., Vohr H. W., Gleichmann E., Lührmann R. Mercuric chloride induces autoantibodies against U3 small nuclear ribonucleoprotein in susceptible mice. Proc Natl Acad Sci U S A. 1989 Jan;86(1):237–241. doi: 10.1073/pnas.86.1.237. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Savino R., Gerbi S. A. In vivo disruption of Xenopus U3 snRNA affects ribosomal RNA processing. EMBO J. 1990 Jul;9(7):2299–2308. doi: 10.1002/j.1460-2075.1990.tb07401.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Schimmang T., Tollervey D., Kern H., Frank R., Hurt E. C. A yeast nucleolar protein related to mammalian fibrillarin is associated with small nucleolar RNA and is essential for viability. EMBO J. 1989 Dec 20;8(13):4015–4024. doi: 10.1002/j.1460-2075.1989.tb08584.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Selzer P. M., Webster P., Duszenko M. Influence of Ca2+ depletion on cytoskeleton and nucleolus morphology in Trypanosoma brucei. Eur J Cell Biol. 1991 Oct;56(1):104–112. [PubMed] [Google Scholar]
  36. Shumard C. M., Eichler D. C. Ribosomal RNA processing. Limited cleavages of mouse preribosomal RNA by a nucleolar endoribonuclease include the early +650 processing site. J Biol Chem. 1988 Dec 25;263(36):19346–19352. [PubMed] [Google Scholar]
  37. Shumard C. M., Torres C., Eichler D. C. In vitro processing at the 3'-terminal region of pre-18S rRNA by a nucleolar endoribonuclease. Mol Cell Biol. 1990 Aug;10(8):3868–3872. doi: 10.1128/mcb.10.8.3868. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Spencer D. F., Collings J. C., Schnare M. N., Gray M. W. Multiple spacer sequences in the nuclear large subunit ribosomal RNA gene of Crithidia fasciculata. EMBO J. 1987 Apr;6(4):1063–1071. doi: 10.1002/j.1460-2075.1987.tb04859.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Stroke I. L., Weiner A. M. The 5' end of U3 snRNA can be crosslinked in vivo to the external transcribed spacer of rat ribosomal RNA precursors. J Mol Biol. 1989 Dec 5;210(3):497–512. doi: 10.1016/0022-2836(89)90126-5. [DOI] [PubMed] [Google Scholar]
  40. Tollervey D. A yeast small nuclear RNA is required for normal processing of pre-ribosomal RNA. EMBO J. 1987 Dec 20;6(13):4169–4175. doi: 10.1002/j.1460-2075.1987.tb02763.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Tollervey D., Hurt E. C. The role of small nucleolar ribonucleoproteins in ribosome synthesis. Mol Biol Rep. 1990;14(2-3):103–106. doi: 10.1007/BF00360433. [DOI] [PubMed] [Google Scholar]
  42. Tollervey D., Lehtonen H., Carmo-Fonseca M., Hurt E. C. The small nucleolar RNP protein NOP1 (fibrillarin) is required for pre-rRNA processing in yeast. EMBO J. 1991 Mar;10(3):573–583. doi: 10.1002/j.1460-2075.1991.tb07984.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Trinh-Rohlik Q., Maxwell E. S. Homologous genes for mouse 4.5S hybRNA are found in all eukaryotes and their low molecular weight RNA transcripts intermolecularly hybridize with eukaryotic 18S ribosomal RNAs. Nucleic Acids Res. 1988 Jul 11;16(13):6041–6056. doi: 10.1093/nar/16.13.6041. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Tschudi C., Krainer A. R., Ullu E. The U6 small nuclear RNA from Trypanosoma brucei. Nucleic Acids Res. 1988 Dec 9;16(23):11375–11375. doi: 10.1093/nar/16.23.11375. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Tschudi C., Richards F. F., Ullu E. The U2 RNA analogue of Trypanosoma brucei gambiense: implications for a splicing mechanism in trypanosomes. Nucleic Acids Res. 1986 Nov 25;14(22):8893–8903. doi: 10.1093/nar/14.22.8893. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Tschudi C., Ullu E. Destruction of U2, U4, or U6 small nuclear RNA blocks trans splicing in trypanosome cells. Cell. 1990 May 4;61(3):459–466. doi: 10.1016/0092-8674(90)90527-l. [DOI] [PubMed] [Google Scholar]
  47. Tyc K., Steitz J. A. U3, U8 and U13 comprise a new class of mammalian snRNPs localized in the cell nucleolus. EMBO J. 1989 Oct;8(10):3113–3119. doi: 10.1002/j.1460-2075.1989.tb08463.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. White T. C., Rudenko G., Borst P. Three small RNAs within the 10 kb trypanosome rRNA transcription unit are analogous to domain VII of other eukaryotic 28S rRNAs. Nucleic Acids Res. 1986 Dec 9;14(23):9471–9489. doi: 10.1093/nar/14.23.9471. [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. Zagorski J., Tollervey D., Fournier M. J. Characterization of an SNR gene locus in Saccharomyces cerevisiae that specifies both dispensible and essential small nuclear RNAs. Mol Cell Biol. 1988 Aug;8(8):3282–3290. doi: 10.1128/mcb.8.8.3282. [DOI] [PMC free article] [PubMed] [Google Scholar]

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