Abstract.
Ornithine decarboxylase (ODC) is the ratelimiting enzyme in the biosynthesis of polyamines, which are required for optimal cell growth and proliferation. ODC is overexpressed in many tumors and, conversely, its overexpression induces transformation. We have previously reported that ODC mRNA alternative splicing relieves the translation repression normally imposed by a long and structured 5′ untranslated region (UTR), and that the ODC 5′ UTR contains an internal ribosome entry site (IRES). Here we show that ODC IRES activity is enhanced following inclusion of alternative sequences generated by splicing at cryptic acceptor sites. Furthermore, the alternative ODC IRES is more sensitive to cell-cycledependent changes in the rate of translation. These findings uncover a new biological property of differentially spliced transcripts. This is the first example of alternative splicing that modulates mRNA translation through the cell cycle in a cap-independent manner.
Similar content being viewed by others
Author information
Authors and Affiliations
Corresponding author
Additional information
Received 14 January 2005; received after revision 10 March 2005; accepted 23 March 2005
Rights and permissions
About this article
Cite this article
Pyronnet, S., Pradayrol, L. & Sonenberg, N. Alternative splicing facilitates internal ribosome entry on the ornithine decarboxylase mRNA. CMLS, Cell. Mol. Life Sci. 62, 1267–1274 (2005). https://doi.org/10.1007/s00018-005-5020-8
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00018-005-5020-8