抄録
Gene expressions are regulated in various steps at transcriptional and post-transcriptional levels. Particularly, alteration of translational initiation step is thought to be very important to synthesize desired proteins quantitatively. This step is strongly influenced by the structure of 5'-UTRs. To estimate the effect of 5'-UTRs on translational efficiencies, we have designed a transient transformation-based assay system in which tobacco BY2, Arabidopsis T87 and rice suspension cultured cells were used as hosts, and GUS gene as a reporter. In this system, when the 5'-UTR of the BY2 alcohol dehydrogenase gene was inserted upstream of translational initiation site, the GUS expressions in BY2 and T87 increased about 30- to 100- fold than control plasmid pBI221. This 5'-UTR functioned also in stable transformants. However, in rice cultured cells, the increase was not so high. Effective 5'-UTRs will be applied to improve productivity in plant cells.
