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. 2001 Feb;7(2):207–219. doi: 10.1017/s1355838201001625

snoRNA nuclear import and potential for cotranscriptional function in pre-rRNA processing.

B A Peculis 1
PMCID: PMC1370079  PMID: 11233978

Abstract

Several snoRNAs are essential for the sequence of cleavage events required to produce the mature forms of 18S, 5.8S, and 28S rRNA from the large precursor molecule. In the absence of U22, mature 18S rRNA fails to accumulate; U8 snoRNA is essential for accumulation of both 5.8S and 28S rRNA. The mechanisms by which snoRNAs facilitate these cleavage events is not known and might include direct cleavage or assisting the rate or efficiency of ribosome assembly. To learn more about the mechanisms of snoRNA-mediated pre-rRNA processing, an examination of the kinetics of pre-rRNA processing in Xenopus oocytes was undertaken. Correct pre-rRNA processing can be restored in snoRNA-depleted oocytes following cytoplasmic injection of the corresponding in vitro-synthesized snoRNA. Analysis of the kinetics of pre-rRNA processing in these snoRNA-rescue experiments demonstrated that the rate of accumulation of mature rRNAs was slower than that seen in untreated oocytes. The snoRNAs were imported into the nucleus at a rate and overall efficiency less than that of U1 snRNA, used as a control for import. However, sufficient levels of snoRNA were present in the nucleus to yield a functional phenotype (rescue of rRNA processing) several hours before the snoRNAs were directly detectable in the nucleus via autoradiography. This indicated that very low amounts of the snoRNA in the nucleus were sufficient for rescue. Finally, transcriptional inhibitors were used to separate transcription and processing. Failure to rescue snoRNA-mediated processing of pre-accumulated precursors is consistent with a scenario in which U8 and U22 must be present during transcription of pre-rRNA.

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Selected References

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  1. Adamson E. D., Woodland H. R. Changes in the rate of histone synthesis during oocyte maturation and very early development of Xenopus laevis. Dev Biol. 1977 May;57(1):136–149. doi: 10.1016/0012-1606(77)90360-8. [DOI] [PubMed] [Google Scholar]
  2. Azum-Gélade M. C., Noaillac-Depeyre J., Caizergues-Ferrer M., Gas N. Cell cycle redistribution of U3 snRNA and fibrillarin. Presence in the cytoplasmic nucleolus remnant and in the prenucleolar bodies at telophase. J Cell Sci. 1994 Feb;107(Pt 2):463–475. doi: 10.1242/jcs.107.2.463. [DOI] [PubMed] [Google Scholar]
  3. Baserga S. J., Gilmore-Hebert M., Yang X. W. Distinct molecular signals for nuclear import of the nucleolar snRNA, U3. Genes Dev. 1992 Jun;6(6):1120–1130. doi: 10.1101/gad.6.6.1120. [DOI] [PubMed] [Google Scholar]
  4. 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]
  5. Beltrame M., Henry Y., Tollervey D. Mutational analysis of an essential binding site for the U3 snoRNA in the 5' external transcribed spacer of yeast pre-rRNA. Nucleic Acids Res. 1994 Nov 25;22(23):5139–5147. doi: 10.1093/nar/22.23.5139. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Birkenmeier E. H., Brown D. D., Jordan E. A nuclear extract of Xenopus laevis oocytes that accurately transcribes 5S RNA genes. Cell. 1978 Nov;15(3):1077–1086. doi: 10.1016/0092-8674(78)90291-x. [DOI] [PubMed] [Google Scholar]
  7. Cavaillé J., Nicoloso M., Bachellerie J. P. Targeted ribose methylation of RNA in vivo directed by tailored antisense RNA guides. Nature. 1996 Oct 24;383(6602):732–735. doi: 10.1038/383732a0. [DOI] [PubMed] [Google Scholar]
  8. Cheng Y., Dahlberg J. E., Lund E. Diverse effects of the guanine nucleotide exchange factor RCC1 on RNA transport. Science. 1995 Mar 24;267(5205):1807–1810. doi: 10.1126/science.7534442. [DOI] [PubMed] [Google Scholar]
  9. Gall J. G., Murphy C., Callan H. G., Wu Z. A. Lampbrush chromosomes. Methods Cell Biol. 1991;36:149–166. [PubMed] [Google Scholar]
  10. Ganot P., Bortolin M. L., Kiss T. Site-specific pseudouridine formation in preribosomal RNA is guided by small nucleolar RNAs. Cell. 1997 May 30;89(5):799–809. doi: 10.1016/s0092-8674(00)80263-9. [DOI] [PubMed] [Google Scholar]
  11. Glibetic M., Larson D. E., Sienna N., Bachellerie J. P., Sells B. H. Regulation of U3 snRNA expression during myoblast differentiation. Exp Cell Res. 1992 Sep;202(1):183–189. doi: 10.1016/0014-4827(92)90418-8. [DOI] [PubMed] [Google Scholar]
  12. Hadjiolova K. V., Nicoloso M., Mazan S., Hadjiolov A. A., Bachellerie J. P. Alternative pre-rRNA processing pathways in human cells and their alteration by cycloheximide inhibition of protein synthesis. Eur J Biochem. 1993 Feb 15;212(1):211–215. doi: 10.1111/j.1432-1033.1993.tb17652.x. [DOI] [PubMed] [Google Scholar]
  13. Haselbeck R. C., Greer C. L. Minimum intron requirements for tRNA splicing and nuclear transport in Xenopus oocytes. Biochemistry. 1993 Aug 24;32(33):8575–8581. doi: 10.1021/bi00084a026. [DOI] [PubMed] [Google Scholar]
  14. Henry Y., Wood H., Morrissey J. P., Petfalski E., Kearsey S., Tollervey D. The 5' end of yeast 5.8S rRNA is generated by exonucleases from an upstream cleavage site. EMBO J. 1994 May 15;13(10):2452–2463. doi: 10.1002/j.1460-2075.1994.tb06530.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Jiménez-García L. F., Segura-Valdez M. L., Ochs R. L., Rothblum L. I., Hannan R., Spector D. L. Nucleologenesis: U3 snRNA-containing prenucleolar bodies move to sites of active pre-rRNA transcription after mitosis. Mol Biol Cell. 1994 Sep;5(9):955–966. doi: 10.1091/mbc.5.9.955. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Kiss-László Z., Henry Y., Bachellerie J. P., Caizergues-Ferrer M., Kiss T. Site-specific ribose methylation of preribosomal RNA: a novel function for small nucleolar RNAs. Cell. 1996 Jun 28;85(7):1077–1088. doi: 10.1016/s0092-8674(00)81308-2. [DOI] [PubMed] [Google Scholar]
  17. Maden B. E., Hughes J. M. Eukaryotic ribosomal RNA: the recent excitement in the nucleotide modification problem. Chromosoma. 1997 Jun;105(7-8):391–400. doi: 10.1007/BF02510475. [DOI] [PubMed] [Google Scholar]
  18. Matera A. G., Tycowski K. T., Steitz J. A., Ward D. C. Organization of small nucleolar ribonucleoproteins (snoRNPs) by fluorescence in situ hybridization and immunocytochemistry. Mol Biol Cell. 1994 Dec;5(12):1289–1299. doi: 10.1091/mbc.5.12.1289. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Mattaj I. W., Tollervey D., Séraphin B. Small nuclear RNAs in messenger RNA and ribosomal RNA processing. FASEB J. 1993 Jan;7(1):47–53. doi: 10.1096/fasebj.7.1.8422974. [DOI] [PubMed] [Google Scholar]
  20. Mattoccia E., Baldi I. M., Gandini-Attardi D., Ciafrè S., Tocchini-Valentini G. P. Site selection by the tRNA splicing endonuclease of Xenopus laevis. Cell. 1988 Nov 18;55(4):731–738. doi: 10.1016/0092-8674(88)90231-0. [DOI] [PubMed] [Google Scholar]
  21. Maxwell E. S., Fournier M. J. The small nucleolar RNAs. Annu Rev Biochem. 1995;64:897–934. doi: 10.1146/annurev.bi.64.070195.004341. [DOI] [PubMed] [Google Scholar]
  22. Michaud N., Goldfarb D. Microinjected U snRNAs are imported to oocyte nuclei via the nuclear pore complex by three distinguishable targeting pathways. J Cell Biol. 1992 Feb;116(4):851–861. doi: 10.1083/jcb.116.4.851. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Murdoch K. J., Allison L. A. A role for ribosomal protein L5 in the nuclear import of 5S rRNA in Xenopus oocytes. Exp Cell Res. 1996 Sep 15;227(2):332–343. doi: 10.1006/excr.1996.0282. [DOI] [PubMed] [Google Scholar]
  24. Ni J., Tien A. L., Fournier M. J. Small nucleolar RNAs direct site-specific synthesis of pseudouridine in ribosomal RNA. Cell. 1997 May 16;89(4):565–573. doi: 10.1016/s0092-8674(00)80238-x. [DOI] [PubMed] [Google Scholar]
  25. Nicoloso M., Qu L. H., Michot B., Bachellerie J. P. Intron-encoded, antisense small nucleolar RNAs: the characterization of nine novel species points to their direct role as guides for the 2'-O-ribose methylation of rRNAs. J Mol Biol. 1996 Jul 12;260(2):178–195. doi: 10.1006/jmbi.1996.0391. [DOI] [PubMed] [Google Scholar]
  26. Peculis B. A., Mount S. M. Ribosomal RNA: small nucleolar RNAs make their mark. Curr Biol. 1996 Nov 1;6(11):1413–1415. doi: 10.1016/s0960-9822(96)00745-2. [DOI] [PubMed] [Google Scholar]
  27. Peculis B. A., Steitz J. A. Disruption of U8 nucleolar snRNA inhibits 5.8S and 28S rRNA processing in the Xenopus oocyte. Cell. 1993 Jun 18;73(6):1233–1245. doi: 10.1016/0092-8674(93)90651-6. [DOI] [PubMed] [Google Scholar]
  28. Peculis B. A., Steitz J. A. Sequence and structural elements critical for U8 snRNP function in Xenopus oocytes are evolutionarily conserved. Genes Dev. 1994 Sep 15;8(18):2241–2255. doi: 10.1101/gad.8.18.2241. [DOI] [PubMed] [Google Scholar]
  29. Peculis B. A. The sequence of the 5' end of the U8 small nucleolar RNA is critical for 5.8S and 28S rRNA maturation. Mol Cell Biol. 1997 Jul;17(7):3702–3713. doi: 10.1128/mcb.17.7.3702. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Peculis B. RNA processing: pocket guides to ribosomal RNA. Curr Biol. 1997 Aug 1;7(8):R480–R482. doi: 10.1016/s0960-9822(06)00242-9. [DOI] [PubMed] [Google Scholar]
  31. Peng H. B. Xenopus laevis: Practical uses in cell and molecular biology. Solutions and protocols. Methods Cell Biol. 1991;36:657–662. [PubMed] [Google Scholar]
  32. Puvion-Dutilleul F., Mazan S., Nicoloso M., Pichard E., Bachellerie J. P., Puvion E. Alterations of nucleolar ultrastructure and ribosome biogenesis by actinomycin D. Implications for U3 snRNP function. Eur J Cell Biol. 1992 Jun;58(1):149–162. [PubMed] [Google Scholar]
  33. Puvion-Dutilleul F., Puvion E., Bachellerie J. P. Early stages of pre-rRNA formation within the nucleolar ultrastructure of mouse cells studied by in situ hybridization with a 5'ETS leader probe. Chromosoma. 1997 Jun;105(7-8):496–505. doi: 10.1007/BF02510486. [DOI] [PubMed] [Google Scholar]
  34. 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]
  35. Shiokawa K., Fu Y., Yamana K. Acceleration of the rate of processing of 40 S pre-rRNA during Xenopus laevis embryogenesis. Dev Biol. 1987 Aug;122(2):586–588. doi: 10.1016/0012-1606(87)90322-8. [DOI] [PubMed] [Google Scholar]
  36. Sienna N., Larson D. E., Sells B. H. Altered subcellular distribution of U3 snRNA in response to serum in mouse fibroblasts. Exp Cell Res. 1996 Aug 25;227(1):98–105. doi: 10.1006/excr.1996.0254. [DOI] [PubMed] [Google Scholar]
  37. Speckmann W., Narayanan A., Terns R., Terns M. P. Nuclear retention elements of U3 small nucleolar RNA. Mol Cell Biol. 1999 Dec;19(12):8412–8421. doi: 10.1128/mcb.19.12.8412. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Steitz J. A., Tycowski K. T. Small RNA chaperones for ribosome biogenesis. Science. 1995 Dec 8;270(5242):1626–1627. doi: 10.1126/science.270.5242.1626. [DOI] [PubMed] [Google Scholar]
  39. Terns M. P., Dahlberg J. E. Retention and 5' cap trimethylation of U3 snRNA in the nucleus. Science. 1994 May 13;264(5161):959–961. doi: 10.1126/science.8178154. [DOI] [PubMed] [Google Scholar]
  40. Terns M. P., Goldfarb D. S. Nuclear transport of RNAs in microinjected Xenopus oocytes. Methods Cell Biol. 1998;53:559–589. doi: 10.1016/s0091-679x(08)60895-x. [DOI] [PubMed] [Google Scholar]
  41. Terns M. P., Grimm C., Lund E., Dahlberg J. E. A common maturation pathway for small nucleolar RNAs. EMBO J. 1995 Oct 2;14(19):4860–4871. doi: 10.1002/j.1460-2075.1995.tb00167.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Tycowski K. T., Shu M. D., Steitz J. A. Requirement for intron-encoded U22 small nucleolar RNA in 18S ribosomal RNA maturation. Science. 1994 Dec 2;266(5190):1558–1561. doi: 10.1126/science.7985025. [DOI] [PubMed] [Google Scholar]
  43. Venema J., Tollervey D. Ribosome synthesis in Saccharomyces cerevisiae. Annu Rev Genet. 1999;33:261–311. doi: 10.1146/annurev.genet.33.1.261. [DOI] [PubMed] [Google Scholar]
  44. Weisenberger D., Scheer U. A possible mechanism for the inhibition of ribosomal RNA gene transcription during mitosis. J Cell Biol. 1995 May;129(3):561–575. doi: 10.1083/jcb.129.3.561. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Yang H., Moss M. L., Lund E., Dahlberg J. E. Nuclear processing of the 3'-terminal nucleotides of pre-U1 RNA in Xenopus laevis oocytes. Mol Cell Biol. 1992 Apr;12(4):1553–1560. doi: 10.1128/mcb.12.4.1553. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Zanchin N. I., Goldfarb D. S. The exosome subunit Rrp43p is required for the efficient maturation of 5.8S, 18S and 25S rRNA. Nucleic Acids Res. 1999 Mar 1;27(5):1283–1288. doi: 10.1093/nar/27.5.1283. [DOI] [PMC free article] [PubMed] [Google Scholar]

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