| 摘要 |
<p>A method of search for and identification of a eukaryotic IRES element active in cap-independent translation of RNA in eukaryiotic cells is provided, comprising the following steps: i)screening eukaryotic mRNA sequences or corresponding DNA sequences for a potential IRES element having a block of nucleotides having: a) a length of at least 30 nucleotides; b) an adenine nucleotide content of at least 40 mol-%; and c) a pyrimidine nucleotide content of less than 40 mol-%; ii) inserting said potential IRES element into a linear dicistronic construct between an upstream gene and a downstream GUS reporter gene, whereby said potential IRES element is positioned for IRES-dependent translation of said downstream GUS gene and whereby said upstream gene is preceded by a stable hairpin structure to prevent IRES-independent translation of said genes; and iii) testing said potential IRES element for IRES-dependent translation of said GUS gene in a rabbit reticulocyte lysate or in a wheat germ extract in vitro translation assay, whereby GUS gene expression is quantitated preferably relative to a construct having a reference IRES element or a non-IRES element between said upstream gene and said GUS gene.</p> |
