The beta-tubulin genes of Paramecium are interrupted by two 27 bp introns
Abstract
In the ciliate Paramecium tetraurelia, the analysis of the tubulin gene family has revealed the existence of four alpha and three beta genes. We show here that the coding sequence of the first beta-tubulin gene to be cloned and sequenced is interrupted by two short non-coding sequences of 27 bp each, which present at their extremities the pairs GT/AG, characteristic of eukaryotic pre-mRNA introns, and the internal pentanucleotide TTAAT, consensual in Tetrahymena introns. We demonstrate by PCR experiments that the three macronuclear beta-tubulin genes contain these sequences in similar positions, thereby ruling out the possibility that these sequences are ciliate IES present in the micronucleus and eliminated in the transcriptionally active macronucleus. S1 mapping analysis and mRNA sequencing show that the sequences are absent from the beta-tubulin transcripts. These sequences are the first introns described in protein encoding genes in P. tetraurelia and the shortest known introns altogether.

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- Barahona I., Soares H., Cyrne L., Penque D., Denoulet P., Rodrigues-Pousada C. Sequence of one alpha- and two beta-tubulin genes of Tetrahymena pyriformis. Structural and functional relationships with other eukaryotic tubulin genes. J Mol Biol. 1988 Aug 5;202(3):365–382. doi: 10.1016/0022-2836(88)90271-9. [DOI] [PubMed] [Google Scholar]
- Baroin A., Perasso R., Qu L. H., Brugerolle G., Bachellerie J. P., Adoutte A. Partial phylogeny of the unicellular eukaryotes based on rapid sequencing of a portion of 28S ribosomal RNA. Proc Natl Acad Sci U S A. 1988 May;85(10):3474–3478. doi: 10.1073/pnas.85.10.3474. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baroin A., Prat A., Caron F. Telomeric site position heterogeneity in macronuclear DNA of Paramecium primaurelia. Nucleic Acids Res. 1987 Feb 25;15(4):1717–1728. doi: 10.1093/nar/15.4.1717. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blumenthal T., Thomas J. Cis and trans mRNA splicing in C. elegans. Trends Genet. 1988 Nov;4(11):305–308. doi: 10.1016/0168-9525(88)90107-2. [DOI] [PubMed] [Google Scholar]
- Bourgain F. M., Katinka M. D. Telomeres inhibit end to end fusion and enhance maintenance of linear DNA molecules injected into the Paramecium primaurelia macronucleus. Nucleic Acids Res. 1991 Apr 11;19(7):1541–1547. doi: 10.1093/nar/19.7.1541. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caron F., Meyer E. Does Paramecium primaurelia use a different genetic code in its macronucleus? Nature. 1985 Mar 14;314(6007):185–188. doi: 10.1038/314185a0. [DOI] [PubMed] [Google Scholar]
- Cavalier-Smith T. Intron phylogeny: a new hypothesis. Trends Genet. 1991 May;7(5):145–148. [PubMed] [Google Scholar]
- Cech T. R., Zaug A. J., Grabowski P. J. In vitro splicing of the ribosomal RNA precursor of Tetrahymena: involvement of a guanosine nucleotide in the excision of the intervening sequence. Cell. 1981 Dec;27(3 Pt 2):487–496. doi: 10.1016/0092-8674(81)90390-1. [DOI] [PubMed] [Google Scholar]
- Church G. M., Gilbert W. Genomic sequencing. Proc Natl Acad Sci U S A. 1984 Apr;81(7):1991–1995. doi: 10.1073/pnas.81.7.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Conzelmann K. K., Helftenbein E. Nucleotide sequence and expression of two beta-tubulin genes in Stylonychia lemnae. J Mol Biol. 1987 Dec 20;198(4):643–653. doi: 10.1016/0022-2836(87)90207-5. [DOI] [PubMed] [Google Scholar]
- Csank C., Taylor F. M., Martindale D. W. Nuclear pre-mRNA introns: analysis and comparison of intron sequences from Tetrahymena thermophila and other eukaryotes. Nucleic Acids Res. 1990 Sep 11;18(17):5133–5141. doi: 10.1093/nar/18.17.5133. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Devereux J., Haeberli P., Smithies O. A comprehensive set of sequence analysis programs for the VAX. Nucleic Acids Res. 1984 Jan 11;12(1 Pt 1):387–395. doi: 10.1093/nar/12.1part1.387. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dibb N. J., Newman A. J. Evidence that introns arose at proto-splice sites. EMBO J. 1989 Jul;8(7):2015–2021. doi: 10.1002/j.1460-2075.1989.tb03609.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Frischauf A. M., Lehrach H., Poustka A., Murray N. Lambda replacement vectors carrying polylinker sequences. J Mol Biol. 1983 Nov 15;170(4):827–842. doi: 10.1016/s0022-2836(83)80190-9. [DOI] [PubMed] [Google Scholar]
- Gilbert W., Marchionni M., McKnight G. On the antiquity of introns. Cell. 1986 Jul 18;46(2):151–153. doi: 10.1016/0092-8674(86)90730-0. [DOI] [PubMed] [Google Scholar]
- Goodall G. J., Filipowicz W. The AU-rich sequences present in the introns of plant nuclear pre-mRNAs are required for splicing. Cell. 1989 Aug 11;58(3):473–483. doi: 10.1016/0092-8674(89)90428-5. [DOI] [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]
- Greslin A. F., Prescott D. M., Oka Y., Loukin S. H., Chappell J. C. Reordering of nine exons is necessary to form a functional actin gene in Oxytricha nova. Proc Natl Acad Sci U S A. 1989 Aug;86(16):6264–6268. doi: 10.1073/pnas.86.16.6264. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hanyu N., Kuchino Y., Nishimura S., Beier H. Dramatic events in ciliate evolution: alteration of UAA and UAG termination codons to glutamine codons due to anticodon mutations in two Tetrahymena tRNAs. EMBO J. 1986 Jun;5(6):1307–1311. doi: 10.1002/j.1460-2075.1986.tb04360.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hawkins J. D. A survey on intron and exon lengths. Nucleic Acids Res. 1988 Nov 11;16(21):9893–9908. doi: 10.1093/nar/16.21.9893. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Helftenbein E., Müller E. Both alpha-tubulin genes are transcriptionally active in Stylonychia lemnae. Curr Genet. 1988 May;13(5):425–432. doi: 10.1007/BF00365664. [DOI] [PubMed] [Google Scholar]
- Helftenbein E. Nucleotide sequence of a macronuclear DNA molecule coding for alpha-tubulin from the ciliate Stylonychia lemnae. Special codon usage: TAA is not a translation termination codon. Nucleic Acids Res. 1985 Jan 25;13(2):415–433. doi: 10.1093/nar/13.2.415. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Herrick G., Hunter D., Williams K., Kotter K. Alternative processing during development of a macronuclear chromosome family in Oxytricha fallax. Genes Dev. 1987 Dec;1(10):1047–1058. doi: 10.1101/gad.1.10.1047. [DOI] [PubMed] [Google Scholar]
- Horowitz S., Bowen J. K., Bannon G. A., Gorovsky M. A. Unusual features of transcribed and translated regions of the histone H4 gene family of Tetrahymena thermophila. Nucleic Acids Res. 1987 Jan 12;15(1):141–160. doi: 10.1093/nar/15.1.141. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kink J. A., Maley M. E., Preston R. R., Ling K. Y., Wallen-Friedman M. A., Saimi Y., Kung C. Mutations in paramecium calmodulin indicate functional differences between the C-terminal and N-terminal lobes in vivo. Cell. 1990 Jul 13;62(1):165–174. doi: 10.1016/0092-8674(90)90250-i. [DOI] [PubMed] [Google Scholar]
- Klobutcher L. A., Jahn C. L., Prescott D. M. Internal sequences are eliminated from genes during macronuclear development in the ciliated protozoan Oxytricha nova. Cell. 1984 Apr;36(4):1045–1055. doi: 10.1016/0092-8674(84)90054-0. [DOI] [PubMed] [Google Scholar]
- Little M., Seehaus T. Comparative analysis of tubulin sequences. Comp Biochem Physiol B. 1988;90(4):655–670. doi: 10.1016/0305-0491(88)90320-3. [DOI] [PubMed] [Google Scholar]
- Martindale D. W. Codon usage in Tetrahymena and other ciliates. J Protozool. 1989 Jan-Feb;36(1):29–34. doi: 10.1111/j.1550-7408.1989.tb02679.x. [DOI] [PubMed] [Google Scholar]
- Meyer F., Schmidt H. J., Plümper E., Hasilik A., Mersmann G., Meyer H. E., Engström A., Heckmann K. UGA is translated as cysteine in pheromone 3 of Euplotes octocarinatus. Proc Natl Acad Sci U S A. 1991 May 1;88(9):3758–3761. doi: 10.1073/pnas.88.9.3758. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nielsen E., You Y., Forney J. Cysteine residue periodicity is a conserved structural feature of variable surface proteins from Paramecium tetraurelia. J Mol Biol. 1991 Dec 20;222(4):835–841. doi: 10.1016/0022-2836(91)90573-o. [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]
- Prat A. Conserved sequences flank variable tandem repeats in two alleles of the G surface protein of Paramecium primaurelia. J Mol Biol. 1990 Feb 5;211(3):521–535. doi: 10.1016/0022-2836(90)90263-L. [DOI] [PubMed] [Google Scholar]
- Prat A., Katinka M., Caron F., Meyer E. Nucleotide sequence of the Paramecium primaurelia G surface protein. A huge protein with a highly periodic structure. J Mol Biol. 1986 May 5;189(1):47–60. doi: 10.1016/0022-2836(86)90380-3. [DOI] [PubMed] [Google Scholar]
- Preer J. R., Jr, Preer L. B., Rudman B. M., Barnett A. J. Deviation from the universal code shown by the gene for surface protein 51A in Paramecium. Nature. 1985 Mar 14;314(6007):188–190. doi: 10.1038/314188a0. [DOI] [PubMed] [Google Scholar]
- Rautmann G., Matthes H. W., Gait M. J., Breathnach R. Synthetic donor and acceptor splice sites function in an RNA polymerase B (II) transcription unit. EMBO J. 1984 Sep;3(9):2021–2028. doi: 10.1002/j.1460-2075.1984.tb02085.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sogin M. L., Elwood H. J., Gunderson J. H. Evolutionary diversity of eukaryotic small-subunit rRNA genes. Proc Natl Acad Sci U S A. 1986 Mar;83(5):1383–1387. doi: 10.1073/pnas.83.5.1383. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Spangler E. A., Ryan T., Blackburn E. H. Developmentally regulated telomere addition in Tetrahymena thermophila. Nucleic Acids Res. 1988 Jun 24;16(12):5569–5585. doi: 10.1093/nar/16.12.5569. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Treisman R., Novak U., Favaloro J., Kamen R. Transformation of rat cells by an altered polyoma virus genome expressing only the middle-T protein. Nature. 1981 Aug 13;292(5824):595–600. doi: 10.1038/292595a0. [DOI] [PubMed] [Google Scholar]
- Wieringa B., Hofer E., Weissmann C. A minimal intron length but no specific internal sequence is required for splicing the large rabbit beta-globin intron. Cell. 1984 Jul;37(3):915–925. doi: 10.1016/0092-8674(84)90426-4. [DOI] [PubMed] [Google Scholar]
- Woolford J. L., Jr Nuclear pre-mRNA splicing in yeast. Yeast. 1989 Nov-Dec;5(6):439–457. doi: 10.1002/yea.320050604. [DOI] [PubMed] [Google Scholar]
- Yao M. C., Yao C. H., Monks B. The controlling sequence for site-specific chromosome breakage in Tetrahymena. Cell. 1990 Nov 16;63(4):763–772. doi: 10.1016/0092-8674(90)90142-2. [DOI] [PubMed] [Google Scholar]
- Yu G. L., Blackburn E. H. Developmentally programmed healing of chromosomes by telomerase in Tetrahymena. Cell. 1991 Nov 15;67(4):823–832. doi: 10.1016/0092-8674(91)90077-c. [DOI] [PubMed] [Google Scholar]
- Zahler A. M., Prescott D. M. Telomere terminal transferase activity in the hypotrichous ciliate Oxytricha nova and a model for replication of the ends of linear DNA molecules. Nucleic Acids Res. 1988 Jul 25;16(14B):6953–6972. doi: 10.1093/nar/16.14.6953. [DOI] [PMC free article] [PubMed] [Google Scholar]
- di Rago J. P., Colson A. M. Molecular basis for resistance to antimycin and diuron, Q-cycle inhibitors acting at the Qi site in the mitochondrial ubiquinol-cytochrome c reductase in Saccharomyces cerevisiae. J Biol Chem. 1988 Sep 5;263(25):12564–12570. [PubMed] [Google Scholar]