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. 1988 Jan;8(1):494–496. doi: 10.1128/mcb.8.1.494

The cap of both miniexon-derived RNA and mRNA of trypanosomes is 7-methylguanosine.

R E Sutton 1, J C Boothroyd 1
PMCID: PMC363158  PMID: 3336365

Abstract

Most, if not all, trypanosome mRNAs have the same 35-base sequence at their 5' terminus which is derived from a short RNA (medRNA) probably by the process of trans-splicing. It is of interest, evolutionarily and mechanistically, to determine the chemical structure of the 5' terminus of the precursor (medRNA) and product (mRNA). We demonstrate here that the cap structure of both is most probably 7-methylguanosine in a 5',5' triphosphate linkage, consistent with a precursor/product relationship.

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Selected References

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  1. Banerjee A. K. 5'-terminal cap structure in eucaryotic messenger ribonucleic acids. Microbiol Rev. 1980 Jun;44(2):175–205. doi: 10.1128/mr.44.2.175-205.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Boothroyd J. C. Antigenic variation in African trypanosomes. Annu Rev Microbiol. 1985;39:475–502. doi: 10.1146/annurev.mi.39.100185.002355. [DOI] [PubMed] [Google Scholar]
  3. Boothroyd J. C., Cross G. A. Transcripts coding for variant surface glycoproteins of Trypanosoma brucei have a short, identical exon at their 5' end. Gene. 1982 Dec;20(2):281–289. doi: 10.1016/0378-1119(82)90046-4. [DOI] [PubMed] [Google Scholar]
  4. Borst P. Discontinuous transcription and antigenic variation in trypanosomes. Annu Rev Biochem. 1986;55:701–732. doi: 10.1146/annurev.bi.55.070186.003413. [DOI] [PubMed] [Google Scholar]
  5. Brun R., Schönenberger Cultivation and in vitro cloning or procyclic culture forms of Trypanosoma brucei in a semi-defined medium. Short communication. Acta Trop. 1979 Sep;36(3):289–292. [PubMed] [Google Scholar]
  6. Busch H., Reddy R., Rothblum L., Choi Y. C. SnRNAs, SnRNPs, and RNA processing. Annu Rev Biochem. 1982;51:617–654. doi: 10.1146/annurev.bi.51.070182.003153. [DOI] [PubMed] [Google Scholar]
  7. Campbell D. A., Thornton D. A., Boothroyd J. C. Apparent discontinuous transcription of Trypanosoma brucei variant surface antigen genes. 1984 Sep 27-Oct 3Nature. 311(5984):350–355. doi: 10.1038/311350a0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. De Lange T., Berkvens T. M., Veerman H. J., Frasch A. C., Barry J. D., Borst P. Comparison of the genes coding for the common 5' terminal sequence of messenger RNAs in three trypanosome species. Nucleic Acids Res. 1984 Jun 11;12(11):4431–4443. doi: 10.1093/nar/12.11.4431. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. De Lange T., Liu A. Y., Van der Ploeg L. H., Borst P., Tromp M. C., Van Boom J. H. Tandem repetition of the 5' mini-exon of variant surface glycoprotein genes: a multiple promoter for VSG gene transcription? Cell. 1983 Oct;34(3):891–900. doi: 10.1016/0092-8674(83)90546-9. [DOI] [PubMed] [Google Scholar]
  10. Kooter J. M., De Lange T., Borst P. Discontinuous synthesis of mRNA in trypanosomes. EMBO J. 1984 Oct;3(10):2387–2392. doi: 10.1002/j.1460-2075.1984.tb02144.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Krause M., Hirsh D. A trans-spliced leader sequence on actin mRNA in C. elegans. Cell. 1987 Jun 19;49(6):753–761. doi: 10.1016/0092-8674(87)90613-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Laird P. W., Kooter J. M., Loosbroek N., Borst P. Mature mRNAs of Trypanosoma brucei possess a 5' cap acquired by discontinuous RNA synthesis. Nucleic Acids Res. 1985 Jun 25;13(12):4253–4266. doi: 10.1093/nar/13.12.4253. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Laird P. W., Zomerdijk J. C., de Korte D., Borst P. In vivo labelling of intermediates in the discontinuous synthesis of mRNAs in Trypanosoma brucei. EMBO J. 1987 Apr;6(4):1055–1062. doi: 10.1002/j.1460-2075.1987.tb04858.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Lenardo M. J., Dorfman D. M., Donelson J. E. The spliced leader sequence of Trypanosoma brucei has a potential role as a cap donor structure. Mol Cell Biol. 1985 Sep;5(9):2487–2490. doi: 10.1128/mcb.5.9.2487. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Milhausen M., Nelson R. G., Sather S., Selkirk M., Agabian N. Identification of a small RNA containing the trypanosome spliced leader: a donor of shared 5' sequences of trypanosomatid mRNAs? Cell. 1984 Oct;38(3):721–729. doi: 10.1016/0092-8674(84)90267-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Miller S. I., Landfear S. M., Wirth D. F. Cloning and characterization of a Leishmania gene encoding a RNA spliced leader sequence. Nucleic Acids Res. 1986 Sep 25;14(18):7341–7360. doi: 10.1093/nar/14.18.7341. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Muhich M. L., Hughes D. E., Simpson A. M., Simpson L. The monogenetic kinetoplastid protozoan, Crithidia fasciculata, contains a transcriptionally active, multicopy mini-exon sequence. Nucleic Acids Res. 1987 Apr 10;15(7):3141–3153. doi: 10.1093/nar/15.7.3141. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Murphy W. J., Watkins K. P., Agabian N. Identification of a novel Y branch structure as an intermediate in trypanosome mRNA processing: evidence for trans splicing. Cell. 1986 Nov 21;47(4):517–525. doi: 10.1016/0092-8674(86)90616-1. [DOI] [PubMed] [Google Scholar]
  19. Myers R. M., Larin Z., Maniatis T. Detection of single base substitutions by ribonuclease cleavage at mismatches in RNA:DNA duplexes. Science. 1985 Dec 13;230(4731):1242–1246. doi: 10.1126/science.4071043. [DOI] [PubMed] [Google Scholar]
  20. Nakazato H., Edmonds M. Purification of messenger RNA and heterogeneous nuclear RNA containing poly(a) sequences. Methods Enzymol. 1974;29:431–443. doi: 10.1016/0076-6879(74)29035-9. [DOI] [PubMed] [Google Scholar]
  21. Nelson R. G., Parsons M., Barr P. J., Stuart K., Selkirk M., Agabian N. Sequences homologous to the variant antigen mRNA spliced leader are located in tandem repeats and variable orphons in trypanosoma brucei. Cell. 1983 Oct;34(3):901–909. doi: 10.1016/0092-8674(83)90547-0. [DOI] [PubMed] [Google Scholar]
  22. Nelson R. G., Parsons M., Selkirk M., Newport G., Barr P. J., Agabian N. Sequences homologous to variant antigen mRNA spliced leader in Trypanosomatidae which do not undergo antigenic variation. Nature. 1984 Apr 12;308(5960):665–667. doi: 10.1038/308665a0. [DOI] [PubMed] [Google Scholar]
  23. Pace B., Pace N. R. The chromatography of RNA and oligoribonucleotides on boronate-substituted agarose and polyacrylamide. Anal Biochem. 1980 Sep 1;107(1):128–135. doi: 10.1016/0003-2697(80)90502-3. [DOI] [PubMed] [Google Scholar]
  24. Silberklang M., Gillum A. M., RajBhandary U. L. Use of in vitro 32P labeling in the sequence analysis of nonradioactive tRNAs. Methods Enzymol. 1979;59:58–109. doi: 10.1016/0076-6879(79)59072-7. [DOI] [PubMed] [Google Scholar]
  25. Sutton R. E., Boothroyd J. C. Evidence for trans splicing in trypanosomes. Cell. 1986 Nov 21;47(4):527–535. doi: 10.1016/0092-8674(86)90617-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Walder J. A., Eder P. S., Engman D. M., Brentano S. T., Walder R. Y., Knutzon D. S., Dorfman D. M., Donelson J. E. The 35-nucleotide spliced leader sequence is common to all trypanosome messenger RNA's. Science. 1986 Aug 1;233(4763):569–571. doi: 10.1126/science.3523758. [DOI] [PubMed] [Google Scholar]
  27. Wise J. A., Tollervey D., Maloney D., Swerdlow H., Dunn E. J., Guthrie C. Yeast contains small nuclear RNAs encoded by single copy genes. Cell. 1983 Dec;35(3 Pt 2):743–751. doi: 10.1016/0092-8674(83)90107-1. [DOI] [PubMed] [Google Scholar]

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