Abstract
A major unanswered question in Kinetoplastida parasites is the mechanism of regulating gene expression. Using a transfection system, we have previously shown that the intergenic region of the alpha-tubulin gene of Leishmania enriettii contained sequences required for gene expression. The goal of the work reported here was to determine whether the Leishmania-derived sequences were providing transcriptional control signals or functioning at a post-transcriptional level, most likely in trans-splicing. The chloramphenicol acetyltransferase (cat) gene was used as the reporter gene and was stably introduced into L. enriettii as part of an extrachromosomal element by transfection. We show here that the production of cat mRNA was dramatically dependent on the presence of the intergenic region 5' to the cat gene. The intergenic region could be substituted by a smaller fragment (222 base pairs) that contained the trans-splice acceptor site and an adjacent polypyrimidine tract. This native fragment could be replaced by a synthetic polypyrimidine tract containing an AG site. The native and the synthetic fragments had unidirectional activity. No effect on transcription of the cat gene by the wild-type fragment or the synthetic polypyrimidine was detected. The results indicate that both regions contain signals that affect RNA stability, probably sequences involved in trans-splicing.
Full text
PDF




Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- 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]
- Beck E., Ludwig G., Auerswald E. A., Reiss B., Schaller H. Nucleotide sequence and exact localization of the neomycin phosphotransferase gene from transposon Tn5. Gene. 1982 Oct;19(3):327–336. doi: 10.1016/0378-1119(82)90023-3. [DOI] [PubMed] [Google Scholar]
- 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]
- Bruzik J. P., Steitz J. A. Spliced leader RNA sequences can substitute for the essential 5' end of U1 RNA during splicing in a mammalian in vitro system. Cell. 1990 Sep 7;62(5):889–899. doi: 10.1016/0092-8674(90)90264-f. [DOI] [PubMed] [Google Scholar]
- Cairns B. R., Collard M. W., Landfear S. M. Developmentally regulated gene from Leishmania encodes a putative membrane transport protein. Proc Natl Acad Sci U S A. 1989 Oct;86(20):7682–7686. doi: 10.1073/pnas.86.20.7682. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Foote S. J., Thompson J. K., Cowman A. F., Kemp D. J. Amplification of the multidrug resistance gene in some chloroquine-resistant isolates of P. falciparum. Cell. 1989 Jun 16;57(6):921–930. doi: 10.1016/0092-8674(89)90330-9. [DOI] [PubMed] [Google Scholar]
- Gonzalez A., Lerner T. J., Huecas M., Sosa-Pineda B., Nogueira N., Lizardi P. M. Apparent generation of a segmented mRNA from two separate tandem gene families in Trypanosoma cruzi. Nucleic Acids Res. 1985 Aug 26;13(16):5789–5804. doi: 10.1093/nar/13.16.5789. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Green M. R. Pre-mRNA splicing. Annu Rev Genet. 1986;20:671–708. doi: 10.1146/annurev.ge.20.120186.003323. [DOI] [PubMed] [Google Scholar]
- Grondal E. J., Evers R., Kosubek K., Cornelissen A. W. Characterization of the RNA polymerases of Trypanosoma brucei: trypanosomal mRNAs are composed of transcripts derived from both RNA polymerase II and III. EMBO J. 1989 Nov;8(11):3383–3389. doi: 10.1002/j.1460-2075.1989.tb08502.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hadfield C., Cashmore A. M., Meacock P. A. Sequence and expression characteristics of a shuttle chloramphenicol-resistance marker for Saccharomyces cerevisiae and Escherichia coli. Gene. 1987;52(1):59–70. doi: 10.1016/0378-1119(87)90395-7. [DOI] [PubMed] [Google Scholar]
- Higuchi R. G., Ochman H. Production of single-stranded DNA templates by exonuclease digestion following the polymerase chain reaction. Nucleic Acids Res. 1989 Jul 25;17(14):5865–5865. doi: 10.1093/nar/17.14.5865. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Imboden M. A., Laird P. W., Affolter M., Seebeck T. Transcription of the intergenic regions of the tubulin gene cluster of Trypanosoma brucei: evidence for a polycistronic transcription unit in a eukaryote. Nucleic Acids Res. 1987 Sep 25;15(18):7357–7368. doi: 10.1093/nar/15.18.7357. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johnson P. J., Kooter J. M., Borst P. Inactivation of transcription by UV irradiation of T. brucei provides evidence for a multicistronic transcription unit including a VSG gene. Cell. 1987 Oct 23;51(2):273–281. doi: 10.1016/0092-8674(87)90154-1. [DOI] [PubMed] [Google Scholar]
- Kooter J. M., van der Spek H. J., Wagter R., d'Oliveira C. E., van der Hoeven F., Johnson P. J., Borst P. The anatomy and transcription of a telomeric expression site for variant-specific surface antigens in T. brucei. Cell. 1987 Oct 23;51(2):261–272. doi: 10.1016/0092-8674(87)90153-x. [DOI] [PubMed] [Google Scholar]
- Laban A., Tobin J. F., Curotto de Lafaille M. A., Wirth D. F. Stable expression of the bacterial neor gene in Leishmania enriettii. Nature. 1990 Feb 8;343(6258):572–574. doi: 10.1038/343572a0. [DOI] [PubMed] [Google Scholar]
- Laban A., Wirth D. F. Transfection of Leishmania enriettii and expression of chloramphenicol acetyltransferase gene. Proc Natl Acad Sci U S A. 1989 Dec;86(23):9119–9123. doi: 10.1073/pnas.86.23.9119. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Landfear S. M., McMahon-Pratt D., Wirth D. F. Tandem arrangement of tubulin genes in the protozoan parasite Leishmania enriettii. Mol Cell Biol. 1983 Jun;3(6):1070–1076. doi: 10.1128/mcb.3.6.1070. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Landfear S. M., Miller S. I., Wirth D. F. Transcriptional mapping of Leishmania enrietti tubulin mRNAs. Mol Biochem Parasitol. 1986 Dec;21(3):235–245. doi: 10.1016/0166-6851(86)90129-5. [DOI] [PubMed] [Google Scholar]
- 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]
- Muhich M. L., Boothroyd J. C. Polycistronic transcripts in trypanosomes and their accumulation during heat shock: evidence for a precursor role in mRNA synthesis. Mol Cell Biol. 1988 Sep;8(9):3837–3846. doi: 10.1128/mcb.8.9.3837. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Padgett R. A., Grabowski P. J., Konarska M. M., Seiler S., Sharp P. A. Splicing of messenger RNA precursors. Annu Rev Biochem. 1986;55:1119–1150. doi: 10.1146/annurev.bi.55.070186.005351. [DOI] [PubMed] [Google Scholar]
- Saiki R. K., Bugawan T. L., Horn G. T., Mullis K. B., Erlich H. A. Analysis of enzymatically amplified beta-globin and HLA-DQ alpha DNA with allele-specific oligonucleotide probes. Nature. 1986 Nov 13;324(6093):163–166. doi: 10.1038/324163a0. [DOI] [PubMed] [Google Scholar]
- Sather S., Agabian N. A 5' spliced leader is added in trans to both alpha- and beta-tubulin transcripts in Trypanosoma brucei. Proc Natl Acad Sci U S A. 1985 Sep;82(17):5695–5699. doi: 10.1073/pnas.82.17.5695. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Seebeck T., Whittaker P. A., Imboden M. A., 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. doi: 10.1073/pnas.80.15.4634. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Thomashow L. S., Milhausen M., Rutter W. J., Agabian N. Tubulin genes are tandemly linked and clustered in the genome of trypanosoma brucei. Cell. 1983 Jan;32(1):35–43. doi: 10.1016/0092-8674(83)90494-4. [DOI] [PubMed] [Google Scholar]
- 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]