1887

Abstract

The 5′-cap structure of eukaryotic mRNA is methylated at the terminal guanosine by RNA (guanine- -)-methyltransferase (cap MTase). () and human (also called ) genes are responsible for this enzyme. The homologue was cloned from the pathogenic fungus and named (). When expressed as a fusion with glutathione -transferase (GST), CaAbd1p displayed cap MTase activity and rescued Δ null mutants, indicating that specifies an active cap MTase. Although the human cap MTase binds to the human capping enzyme (Hce1p), which possesses both mRNA guanylyltransferase (mRNA GTase) and mRNA 5′-triphosphatase (mRNA TPase) activities, yeast two-hybrid analysis demonstrated that in yeast neither mRNA GTase nor mRNA TPase physically interacted with the Abd1 protein. Comparison of the amino acid sequences of known and putative cap MTases revealed a highly conserved amino acid sequence motif, Phe/Val-Leu-Asp/Glu-Leu/Met-Xaa-Cys-Gly-Lys-Gly-Gly-Asp-Leu-Xaa-Lys, which encompasses the sequence motif characteristic of divergent methyltransferases. Mutations in CaAbd1p of leucine at the second and the twelfth positions (so far uncharacterized) to alanine severely diminished the enzyme activity and the functionality , whereas those of leucine at the fourth, cysteine at the sixth, lysine at the eighth, and glycine at the tenth positions did not. Furthermore, valine substitution for the twelfth, but not for the second, leucine in that motif abolished the activity and functionality of CaAbd1p. Thus, it appears that leucine at the second and the twelfth positions in the motif, together with a previously identified acidic residue in the third, glycine at the sixth and glutamic acid at the eleventh positions, play important roles in the catalysis, and that side chain length is crucial for the activity at the twelfth position in the motif.

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1999-11-01
2019-10-13
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References

  1. Fauman, E. B. & Shaper, M. A. ( 1996; ). Structure and function of the protein tyrosine phsophatases. Trends Biochem Sci 21, 413-417.[CrossRef]
    [Google Scholar]
  2. Feilotter, H. E., Hannon, G. J., Ruddel, C. J. & Beach, D. ( 1994; ). Construction of an improved host strain for two hybrid screening. Nucleic Acids Res 22, 1502-1503.[CrossRef]
    [Google Scholar]
  3. Gillian-Daniel, D. L., Gray, N. K., Astrom, J., Barkoff, A. & Wickens, M. ( 1998; ). Modifications of the 5′ cap of mRNA during Xenopus oocyte maturation: independence from changes in poly(A) length and impact on translation. Mol Cell Biol 18, 6152-6163.
    [Google Scholar]
  4. Hashimoto-Gotoh, T., Mizuno, T., Ogasahara, Y. & Nakagawa, M. ( 1995; ). An oligodeoxyribonucleotide-directed dual amber method for site-directed mutagenesis. Gene 152, 271-275.[CrossRef]
    [Google Scholar]
  5. Held, W. A., West, K. & Gallagher, J. F. ( 1977; ). Importance of initiation factor preparation in the translation of reovirus and globin mRNA lacking a 5′-terminal 7-methylguanosine. J Biol Chem 252, 8489-8497.
    [Google Scholar]
  6. Ho, C. K., Schwer, B. & Shuman, S. ( 1998; ). Genetic, physical, and functional interactions between the triphosphatase and guanylyltransferase components of the yeast mRNA capping apparatus. Mol Cell Biol 18, 5189-5198.
    [Google Scholar]
  7. Ito, H., Fukuda, Y., Murata, K. & Kimura, A. ( 1983; ). Transformation of intact yeast cells treated with alkali cations. J Bacteriol 153, 163-168.
    [Google Scholar]
  8. Kagan, R. M. & Clarke, S. ( 1994; ). Widespread occurrence of three sequence motifs in diverse S-adenosylmethionine-dependent methyltransferases suggests a common structure for three enzymes. Arch Biochem Biophys 310, 417-427.[CrossRef]
    [Google Scholar]
  9. Koonin, E. V. ( 1993; ). Computer-assisted identification of a putative methyltransferase domain in NS5 protein of flaviviruses and λ2 protein of reovirus. J Gen Virol 74, 733-740.[CrossRef]
    [Google Scholar]
  10. McCracken, S., Fong, N., Rosonina, E. & 8 other authors ( 1997; ). 5′-Capping enzymes are targeted to pre-mRNA by binding to the phosphorylated carboxy-terminal domain of RNA polymerase II. Genes Dev 11, 3306–3318.[CrossRef]
    [Google Scholar]
  11. Mao, X., Schwer, B. & Shuman, S. ( 1995; ). Yeast mRNA cap methyltransferase is a 50-kilodalton protein encoded by an essential gene. Mol Cell Biol 15, 4167-4174.
    [Google Scholar]
  12. Mao, X., Schwer, B. & Shuman, S. ( 1996; ). Mutational analysis of the Saccharomyces cerevisiae ABD1 gene: cap methyltransferase activity is essential for cell growth. Mol Cell Biol 16, 475-480.
    [Google Scholar]
  13. Mizumoto, K. & Lipmann, F. ( 1979; ). Transmethylation and transguanylylation in 5′-RNA capping system isolated from rat liver nuclei. Proc Natl Acad Sci USA 76, 4961-4965.[CrossRef]
    [Google Scholar]
  14. Mizumoto, K. & Kaziro, Y. ( 1987; ). Messenger RNA capping enzymes from eukaryotic cells. Prog Nucleic Acid Res Mol Biol 34, 1-28.
    [Google Scholar]
  15. Pelletier, J., Kaplan, G., Racaniello, V. R. & Sonenberg, N. ( 1988; ). Cap-independent translation of poliovirus mRNA is conferred by sequence elements within the 5′ noncoding region. Mol Cell Biol 8, 1103-1112.
    [Google Scholar]
  16. Pillutla, R. C., Yue, Z., Maldonado, E. & Shatkin, A. J. ( 1998; ). Recombinant human mRNA cap methyltransferase binds capping enzyme/RNA polymerase IIo complexes. J Biol Chem 273, 21443-21446.[CrossRef]
    [Google Scholar]
  17. Sambrook, J., Fritsch, E. F. & Maniatis, T. (1989). Molecular Cloning: a Laboratory Manual, 2nd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.
  18. Santos, M. A. & Tuite, M. F. ( 1995; ). The CUG codon is decoded in vivo as serine and not leucine in Candida albicans. Nucleic Acids Res 23, 1481-1486.[CrossRef]
    [Google Scholar]
  19. Schneider, B. L., Seufert, W., Steiner, B., Yang, Q. H. & Futcher, A. B. ( 1995; ). Use of polymerase chain reaction epitope tagging for protein tagging in Saccharomyces cerevisiae. Yeast 11, 1265-1274.[CrossRef]
    [Google Scholar]
  20. Shibagaki, Y., Itoh, N., Yamada, H., Nagata, S. & Mizumoto, K. ( 1992; ). mRNA capping enzyme: isolation and characterization of the gene encoding mRNA guanylyltransferase subunit from Saccharomyces cerevisiae. J Biol Chem 267, 9521-9528.
    [Google Scholar]
  21. Silva, E., Ullu, E., Kobayashi, R. & Tschudi, C. ( 1998; ). Trypanosome capping enzymes display a novel two-domain structure. Mol Cell Biol 18, 4612-4619.
    [Google Scholar]
  22. Shuman, S. ( 1995; ). Capping enzyme in eukaryotic mRNA synthesis. Prog Nucleic Acid Res Mol Biol 50, 101-129.
    [Google Scholar]
  23. Shuman, S., Liu, Y. & Schwer, B. ( 1994; ). Covalent catalysis in nucleotidyl transfer reaction: essential motifs in Saccharomyces cerevisiae RNA capping enzyme are conserved in Schizosaccharomyces pombe and viral capping enzymes and among polynucleotide ligases. Proc Natl Acad Sci USA 91, 12046-12050.[CrossRef]
    [Google Scholar]
  24. Smith, D. B. & Johnson, K. S. ( 1988; ). Single-step purification of polypeptides expressed in Escherichia coli as fusions with glutathione S-transferase. Gene 67, 31-40.[CrossRef]
    [Google Scholar]
  25. Takagi, T., Moore, C. R., Diehn, F. & Buratowski, S. ( 1997; ). An RNA 5′-triphosphatase related to the protein tyrosine phosphatases. Cell 89, 867-873.[CrossRef]
    [Google Scholar]
  26. Tsukamoto, T., Shibagaki, Y., Imajoh-Ohmi, S., Murakoshi, T., Suzuki, M., Nakamura, A., Gotoh, H. & Mizumoto, K. ( 1997; ). Isolation and characterization of the yeast mRNA capping enzyme β subunit gene encoding RNA 5′-triphosphatase, which is essential for cell viability. Biochem Biophys Res Commun 239, 116-122.[CrossRef]
    [Google Scholar]
  27. Tsukamoto, T., Shibagaki, Y., Murakoshi, T., Suzuki, M., Nakamura, A., Gotoh, H. & Mizumoto, K. ( 1998a; ). Cloning and characterization of two human cDNAs encoding the mRNA capping enzyme. Biochem Biophys Res Commun 243, 101-108.[CrossRef]
    [Google Scholar]
  28. Tsukamoto, T., Shibagaki, Y., Niikura, Y. & Mizumoto, K. ( 1998b; ). Cloning and characterization of three human cDNAs encoding mRNA (guanine-7-)-methyltransferase, an mRNA cap methylase. Biochem Biophys Res Commun 251, 27-34.[CrossRef]
    [Google Scholar]
  29. Wang, S. P. & Shuman, S. ( 1997; ). Structure–function analysis of the mRNA cap methyltransferase of Saccharomyces cerevisiae. J Biol Chem 272, 14683-14689.[CrossRef]
    [Google Scholar]
  30. Wen, Y., Yue, Z. & Shatkin, A. J. ( 1998; ). Mammalian capping enzyme binds RNA and uses protein tyrosine phosphatase mechanism. Proc Natl Acad Sci USA 95, 12226-12231.[CrossRef]
    [Google Scholar]
  31. Yamada-Okabe, T., Shimmi, O., Doi, R., Mizumoto, K., Arisawa, M. & Yamada-Okabe, H. ( 1996; ). Isolation of the mRNA capping enzyme and ferric-reductase-related genes from Candida albicans. Microbiology 142, 2515-2523.[CrossRef]
    [Google Scholar]
  32. Yamada-Okabe, T., Doi, R., Shimmi, O., Arisawa, M. & Yamada-Okabe, H. ( 1998a; ). Isolation and characterization of a human cDNA for mRNA 5′-capping enzyme. Nucleic Acids Res 26, 1700-1706.[CrossRef]
    [Google Scholar]
  33. Yamada-Okabe, T., Mio, T., Matsui, M., Kashima, Y., Arisawa, M. & Yamada-Oakbe, H. ( 1998b; ). Isolation and characterization of the Candida albicans gene for mRNA 5′-triphosphatase: association of mRNA 5′-triphosphatase and mRNA 5′-guanylyltransferase activities is essential for the function of mRNA 5′-capping enzyme in vivo. FEBS Lett 435, 49-54.[CrossRef]
    [Google Scholar]
  34. Yue, Z., Maldonado, E., Pillutla, R., Cho, H., Reinberg, D. & Shatkin, A. ( 1997; ). Mammalian capping enzyme complements mutant Saccharomyces cerevisiae lacking mRNA guanylyltransferase and selectively binds the elongating form of RNA polymerase II. Proc Natl Acad Sci USA 94, 12898-12903.[CrossRef]
    [Google Scholar]
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