Internal initiation of translation of mRNA in the methylotrophic yeast Hansenula polymorpha
Besides regular cap-dependent translation of mRNA, eukaryotes exploit internal initiation of translation driven by internal ribosome entry sites (IRESs). It is supposed that internal initiation provides translation of cellular mRNAs under stress conditions where the cap-dependent initiation is reduced. A number of IRESs have been characterized in mammalian mRNAs, but only a few examples are known in lower eukaryotes, particularly in yeasts. Here we identified two IRESs in the thermotolerant methylotrophic yeast Hansenula polymorpha DL-1. These sites are located in 5′-untranslated regions of genes HPODL_02249 and HPODL_04025 encoding a hypothetical membrane protein and actin-binding protein, respectively. In Saccharomyces cerevisiae cells, both IRESs drive expression of a second gene of a bicistronic mRNA, as well as translation of hairpin-containing monocistronic mRNA. The possibility of spurious splicing or presence of a cryptic promoter in the IRES sequences was ruled out, indicating that expression of a second gene of a bicistronic mRNA was IRESdependent. We evaluated IRES activity of both elements and found that under normal physiological conditions its contribution to the overall translation of the respective mRNAs in yeast cells is about 0.3-0.4%. Therefore, these results suggest that the IRES-dependent translation initiation mechanism exists in Hansenula polymorpha.
KeywordsmRNA translation internal initiation of translation IRES yeast Hansenula polymorpha DL-1
green fluorescent protein
internal ribosome entry site
Unable to display preview. Download preview PDF.
- 1.Jang, S. K., Krausslich, H. G., Nicklin, M. J., Duke, G. M., Palmenberg, A. C., and Wimmer, E. (1988) A segment of the 5' nontranslated region of encephalomyocarditis virus RNA directs internal entry of ribosomes during in vitro translation, J. Virol., 62, 2636–2643.PubMedPubMedCentralGoogle Scholar
- 5.Stoneley, M., and Willis, A. E. (2004) Cellular internal ribosome entry segments: structures, trans-acting factors and regulation of gene expression, Oncogene, 23, 32003207.Google Scholar
- 9.Gilbert, W. V., Zhou, K., Butler, T. K., and Doudna, J. A. (2007) Cap-independent translation is required for starvation-induced differentiation in yeast, Science, 317, 12241227.Google Scholar
- 10.Liang, S., Wang, B., Pan, L., Ye, Y., He, M., Han, S., Zheng, S., Wang, X., and Lin, Y. (2012) Comprehensive structural annotation of Pichia pastoris transcriptome and the response to various carbon sources using deep pairedend RNA sequencing, BMC Genomics, 13, 738.CrossRefPubMedPubMedCentralGoogle Scholar
- 18.Ravin, N. V., Eldarov, M. A., Kadnikov, V. V., Beletsky, A. V., Schneider, J., Mardanova, E. S., Smekalova, E. M., Zvereva, M. I., Dontsova, O. A., Mardanov, A. V., and Skryabin, K. G. (2013) Genome sequence and analysis of methylotrophic yeast Hansenula polymorpha DL1, BMC Genomics, 14, 837.CrossRefPubMedPubMedCentralGoogle Scholar
- 19.Grillo, G., Turi, A., Licciulli, F., Mignone, F., Liuni, S., Banfi, S., Gennarino, V. A., Horner, D. S., Pavesi, G., Picardi, E., and Pesole, G. (2010) TRdb and UTRsite (RELEASE 2010): a collection of sequences and regulatory motifs of the untranslated regions of eukaryotic mRNAs, Nucleic Acids Res., 38, D75–80.CrossRefPubMedPubMedCentralGoogle Scholar
- 20.Altmann, M., Muller, P. P., Wittmer, B., Ruchti, F., Lanker, S., and Trachsel, H. (1993) A Saccharomyces cerevisiae homologue of mammalian translation initiation factor 4B contributes to RNA helicase activity, EMBO J., 12, 39974003.Google Scholar
- 21.Dorokhov, Y. L., Skulachev, M. V., Ivanov, P. A., Zvereva, S. D., Tjulkina, L. G., Merits, A., Gleba, Y. Y., Hohn, T., and Atabekov, J. G. (2002) Polypurine (A)-rich sequences promote cross-kingdom conservation of internal ribosome entry, Proc. Natl. Acad. Sci. USA, 99, 5301–5306.CrossRefPubMedPubMedCentralGoogle Scholar
- 31.Thompson, S. R., Gulyas, K. D., and Sarnow, P. (2001) Internal initiation in Saccharomyces cerevisiae mediated by an initiator tRNA/eIF2-independent internal ribosome entry site element, Proc. Natl. Acad. Sci. USA, 98, 1297212977.Google Scholar
- 33.Beletsky, A. V., Malyavko, A. N., Sukhanova, M. V., Mardanova, E. S., Zvereva, M. E., Mardanov, A. V., Dontsova, O. A., Lavrik, O. I., and Ravin, N. V. (2015) Expression of genes involved in DNA repair and telomere maintenance in the yeast Hansenula polymorpha DL1 under heat stress, Dokl. Biochem. Biophys., 462, 185–188.CrossRefPubMedGoogle Scholar