Abstract
Commonly, treanslation starts from the first initiation codon. It has been reported that there are mRNAs that have short ORFs upstream the major ORF. In this case, these short ORFs, upstream ORF (uORF), are accepted to be regulators of the major ORF because they may affect on its translation. We found that OsMac1 mRNA was composed of three types of splaicing variants with difference in the 5'UTR. There were three uORFs in all splicing variants of OsMac1 mRNA. We analyzed the effect of these mRNAs to translation of major ORF. We constructed a reporter gene encoding β-glucuronitase following 5'UTRs of these splicing variants. Apparent GUS activities were detected in the transformant cells containing each reporter genes. Strength of the GUS activity was different on the transformants. These results suggest that alternative splicing on the mRNA of OsMac1 was involved in regulation of translation of the major ORF.
