Submitted to: Plant Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2001
Publication Date: 5/1/2002
Citation: Feldbrugge, M., Arizti, P., Sullivan M.L., Zamore, P.D., Belasco, J.G., Green, P.G. 2002. Comparative analysis of the plant mRNA- destabilizing element, DST, in mammalian and tobacco cells. Plant Molecular Biology. 49:215-233. Interpretive Summary: Plants and animals control gene expression at many levels. One way gene expression is controlled is at the level of mRNA stability. Individual mRNAs, the intermediate molecules linking genetic information to the production of specific proteins in cells, can be unstable. The less stable an mRNA, the lower the extent the corresponding cellular protein is made. Understanding mRNA stability is important because it can have such a profound impact on gene expression, with implications in such diverse areas as human health to production of useful genetically modified plants. mRNA instability is often mediated by specific sequences, sometimes called elements, within the mRNA. In this study, the function of a plant-derived mRNA instablility element, DST, was examined in both a plant and mammalian system. Although the plant instablility element functioned in mammalian cells, it is likely that different sequences within the element are recognized in mammalian cells. This result indicates that in its natural context, DST is recognized in a manner unique to plants. The data resulting from this study will be useful to scientists working on mRNA stability in a wide variety of organisms.
Technical Abstract: The labile SAUR transcripts from higher plants contain a conserved DST sequence in their 3-untranslated regions. Two copies of a DST sequence from soybean are sufficient to destabilize reporter transcripts in cultured tobacco cells whereas variants bearing mutations in the conserved ATAGAT or GTA regions are inactive. To investigate the potential for conserved recognition components in mammalian and plant cells, we examined the function of this instability determinant in mouse NIH3T3 fibroblasts and tobacco BY2 cells. In fibroblasts, a tetrameric DST element from soybean accelerated deadenylation and decay of a reporter transcript. However, a version mutated in the ATAGAT region was equally effective in this regard, and a tetrameric DST element from Arabidopsis was inactive. In contrast, the soybean DST element was more active as an mRNA instability element than the mutant version and the Arabidopsiselement, when tested as tetramers in tobacco cells. Hence, the plant DST element is not recognized in animal cells with the same sequence requirements as in plant cells. Therefore, its mode of recognition appears to be plant-specific.