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Nucleic Acids Res. Dec 21, 1984; 12(24): 9457–9472.
PMCID: PMC320473

Alpha-amanitin-insensitive transcription of variant surface glycoprotein genes provides further evidence for discontinuous transcription in trypanosomes.

Abstract

Many, if not all, mRNAs in T.brucei start with the same sequence of 35 nucleotides, separately encoded in clustered so-called mini-exon repeats. From these mini-exon repeats a 141-nt precursor RNA with the 35-nt sequence at its 5' end is transcribed. Indirect evidence suggests that this RNA is linked in a second step to pre-mRNA transcripts. We have studied the sensitivity of RNA synthesis to alpha-amanitin in isolated trypanosome nuclei. Transcription of several protein coding genes is almost completely inhibited by a concentration of 5 micrograms alpha-amanitin per ml, whereas strong inhibition of mini-exon transcription is achieved with 200 micrograms alpha-amanitin per ml. In contrast, transcription of genes for variant surface glycoproteins (VSGs) is not inhibited by 1000 micrograms alpha-amanitin per ml, as is transcription of the genes for the major rRNAs. Since the mature VSG mRNAs start with the 35-nt sequence, our results provide additional evidence that the 35-nt sequence and the main part of VSG mRNA are produced from independent transcription units, these are transcribed by (partly) different RNA polymerases.

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Selected References

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  • Vickerman K. Antigenic variation in trypanosomes. Nature. 1978 Jun 22;273(5664):613–617. [PubMed]
  • Borst P, Bernards A, van der Ploeg LH, Michels PA, Liu AY, de Lange T, Kooter JM. The control of variant surface antigen synthesis in trypanosomes. Eur J Biochem. 1983 Dec 15;137(3):383–389. [PubMed]
  • Cross GA. Identification, purification and properties of clone-specific glycoprotein antigens constituting the surface coat of Trypanosoma brucei. Parasitology. 1975 Dec;71(3):393–417. [PubMed]
  • Van der Ploeg LH, Valerio D, De Lange T, Bernards A, Borst P, Grosveld FG. An analysis of cosmid clones of nuclear DNA from Trypanosoma brucei shows that the genes for variant surface glycoproteins are clustered in the genome. Nucleic Acids Res. 1982 Oct 11;10(19):5905–5923. [PMC free article] [PubMed]
  • Borst P, Cross GA. Molecular basis for trypanosome antigenic variation. Cell. 1982 Jun;29(2):291–303. [PubMed]
  • Hoeijmakers JH, Frasch AC, Bernards A, Borst P, Cross GA. Novel expression-linked copies of the genes for variant surface antigens in trypanosomes. Nature. 1980 Mar 6;284(5751):78–80. [PubMed]
  • Pays E, Van Meirvenne N, Le Ray D, Steinert M. Gene duplication and transposition linked to antigenic variation in Trypanosoma brucei. Proc Natl Acad Sci U S A. 1981 May;78(5):2673–2677. [PMC free article] [PubMed]
  • De Lange T, Borst P. Genomic environment of the expression-linked extra copies of genes for surface antigens of Trypanosoma brucei resembles the end of a chromosome. Nature. 1982 Sep 30;299(5882):451–453. [PubMed]
  • Williams RO, Young JR, Majiwa PA. Genomic rearrangements correlated with antigenic variation in Trypanosoma brucei. Nature. 1979 Dec 20;282(5741):847–849. [PubMed]
  • Williams RO, Young JR, Majiwa PA. Genomic environment of T. brucei VSG genes: presence of a minichromosome. Nature. 1982 Sep 30;299(5882):417–421. [PubMed]
  • Young JR, Miller EN, Williams RO, Turner MJ. Are there two classes of VSG gene in Trypanosoma brucei? Nature. 1983 Nov 10;306(5939):196–198. [PubMed]
  • Bernards A, De Lange T, Michels PA, Liu AY, Huisman MJ, Borst P. Two modes of activation of a single surface antigen gene of Trypanosoma brucei. Cell. 1984 Jan;36(1):163–170. [PubMed]
  • Van der Ploeg LH, Schwartz DC, Cantor CR, Borst P. Antigenic variation in Trypanosoma brucei analyzed by electrophoretic separation of chromosome-sized DNA molecules. Cell. 1984 May;37(1):77–84. [PubMed]
  • Michels PA, Van der Ploeg LH, Liu AY, Borst P. The inactivation and reactivation of an expression-linked gene copy for a variant surface glycoprotein in Trypanosoma brucei. EMBO J. 1984 Jun;3(6):1345–1351. [PMC free article] [PubMed]
  • Bernards A, Van der Ploeg LH, Frasch AC, Borst P, Boothroyd JC, Coleman S, Cross GA. Activation of trypanosome surface glycoprotein genes involves a duplication-transposition leading to an altered 3' end. Cell. 1981 Dec;27(3 Pt 2):497–505. [PubMed]
  • Van der Ploeg LH, Liu AY, Michels PA, De Lange T, Borst P, Majumder HK, Weber H, Veeneman GH, Van Boom J. RNA splicing is required to make the messenger RNA for a variant surface antigen in trypanosomes. Nucleic Acids Res. 1982 Jun 25;10(12):3591–3604. [PMC free article] [PubMed]
  • Boothroyd JC, Cross GA. 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. [PubMed]
  • Borst P, Frasch AC, Bernards A, Van der Ploeg LH, Hoeijmakers JH, Arnberg AC, Cross GA. DNA rearrangements involving the genes for variant antigens in Trypanosoma brucei. Cold Spring Harb Symp Quant Biol. 1981;45(Pt 2):935–943. [PubMed]
  • De Lange T, Liu AY, Van der Ploeg LH, Borst P, Tromp MC, Van Boom JH. 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. [PubMed]
  • Nelson RG, Parsons M, Barr PJ, 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. [PubMed]
  • De Lange T, Michels PA, Veerman HJ, Cornelissen AW, Borst P. Many trypanosome messenger RNAs share a common 5' terminal sequence. Nucleic Acids Res. 1984 May 11;12(9):3777–3790. [PMC free article] [PubMed]
  • Parsons M, Nelson RG, Watkins KP, Agabian N. Trypanosome mRNAs share a common 5' spliced leader sequence. Cell. 1984 Aug;38(1):309–316. [PubMed]
  • De Lange T, Berkvens TM, Veerman HJ, Frasch AC, Barry JD, 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. [PMC free article] [PubMed]
  • Nelson RG, Parsons M, Selkirk M, Newport G, Barr PJ, 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. [PubMed]
  • Kooter JM, De Lange T, Borst P. Discontinuous synthesis of mRNA in trypanosomes. EMBO J. 1984 Oct;3(10):2387–2392. [PMC free article] [PubMed]
  • Campbell DA, van Bree MP, Boothroyd JC. The 5'-limit of transposition and upstream barren region of a trypanosome VSG gene: tandem 76 base-pair repeats flanking (TAA)90. Nucleic Acids Res. 1984 Mar 26;12(6):2759–2774. [PMC free article] [PubMed]
  • Chambon P. Eukaryotic nuclear RNA polymerases. Annu Rev Biochem. 1975;44:613–638. [PubMed]
  • Lindell TJ, Weinberg F, Morris PW, Roeder RG, Rutter WJ. Specific inhibition of nuclear RNA polymerase II by alpha-amanitin. Science. 1970 Oct 23;170(3956):447–449. [PubMed]
  • Michels PA, Liu AY, Bernards A, Sloof P, Van der Bijl MM, Schinkel AH, Menke HH, Borst P, Veeneman GH, Tromp MC, et al. Activation of the genes for variant surface glycoproteins 117 and 118 in Trypanosoma brucei. J Mol Biol. 1983 Jun 5;166(4):537–556. [PubMed]
  • Shapiro SZ, Doxsey SJ. Purification of nuclei from a flagellate protozoan, Trypanosoma brucei. Anal Biochem. 1982 Nov 15;127(1):112–115. [PubMed]
  • Lanham SM. Separation of trypanosomes from the blood of infected rats and mice by anion-exchangers. Nature. 1968 Jun 29;218(5148):1273–1274. [PubMed]
  • Wright BM, Edwards AJ, Jones VE. Use of a cell rupturing pump for the preparation of thymocyte subcellular fractions. J Immunol Methods. 1974 Mar;4(2):281–296. [PubMed]
  • Schibler U, Hagenbüchle O, Wellauer PK, Pittet AC. Two promoters of different strengths control the transcription of the mouse alpha-amylase gene Amy-1a in the parotid gland and the liver. Cell. 1983 Jun;33(2):501–508. [PubMed]
  • Hoeijmakers JH, Borst P, van den Burg J, Weissmann C, Cross GA. The isolation of plasmids containing DNA complementary to messenger RNA for variant surface glycoproteins of Trypanosoma brucei. Gene. 1980 Mar;8(4):391–417. [PubMed]
  • Birnboim HC, Doly J. A rapid alkaline extraction procedure for screening recombinant plasmid DNA. Nucleic Acids Res. 1979 Nov 24;7(6):1513–1523. [PMC free article] [PubMed]
  • Overath P, Czichos J, Stock U, Nonnengaesser C. Repression of glycoprotein synthesis and release of surface coat during transformation of Trypanosoma brucei. EMBO J. 1983;2(10):1721–1728. [PMC free article] [PubMed]
  • Thomashow LS, Milhausen M, Rutter WJ, Agabian N. Tubulin genes are tandemly linked and clustered in the genome of trypanosoma brucei. Cell. 1983 Jan;32(1):35–43. [PubMed]
  • Seebeck T, Whittaker PA, Imboden MA, Hardman N, Braun R. Tubulin genes of Trypanosoma brucei: a tightly clustered family of alternating genes. Proc Natl Acad Sci U S A. 1983 Aug;80(15):4634–4638. [PMC free article] [PubMed]
  • Ferguson MA, Cross GA. Myristylation of the membrane form of a Trypanosoma brucei variant surface glycoprotein. J Biol Chem. 1984 Mar 10;259(5):3011–3015. [PubMed]
  • De Lange T, Kooter JM, Michels PA, Borst P. Telomere conversion in trypanosomes. Nucleic Acids Res. 1983 Dec 10;11(23):8149–8165. [PMC free article] [PubMed]
  • Hasan G, Turner MJ, Cordingley JS. Ribosomal RNA genes of Trypanosoma brucei. Cloning of a rRNA gene containing a mobile element. Nucleic Acids Res. 1982 Nov 11;10(21):6747–6761. [PMC free article] [PubMed]

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