title: Evaluation of seed storage-protein gene 5' untranslated regions in enhancing gene expression in transgenic rice seed.
abstract: 5' untranslated regions (UTRs) are important sequence elements that modulate the expression of genes. Using the β-glucuronidase (GUS) reporter gene driven by the GluC promoter for the rice-seed storage-protein glutelin, we evaluated the potential of the 5'-UTRs of six seed storage-protein genes in enhancing the expression levels of the foreign gene in stable transgenic rice lines. All of the 5'-UTRs significantly enhanced the expression level of the GluC promoter without altering its expression pattern. The 5'-UTRs of Glb-1 and GluA-1 increased the expression of GUS by about 3.36- and 3.11-fold, respectively. The two 5'-UTRs downstream of the Glb-1, OsAct2 and CMV35S promoters also increased GUS expression level in stable transgenic rice lines or in transient expression protoplasts. Therefore, the enhancements were independent of the promoter sequence. Real-time quantitative RT-PCR analysis showed that the increase in protein production was not accompanied by alteration in mRNA levels, which suggests that the enhancements were due to increasing the translational efficiencies of the mRNA. The 5'-UTRs of Glb-1 and GluA-1, when combined with strong promoters, might be ideal candidates for high production of recombinant proteins in rice seeds.
authors.affiliation: Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Wen Xian
authors.initials: WX
authors.lastname: Liu
authors.forename: Hua Liang
authors.initials: HL
authors.lastname: Liu
authors.forename: Zhi Jian
authors.initials: ZJ
authors.lastname: Chai
authors.forename: Xiu Ping
authors.initials: XP
authors.lastname: Xu
authors.forename: Yan Ru
authors.initials: YR
authors.lastname: Song
authors.forename: Le Qing
authors.initials: le Q
authors.lastname: Qu
mesh_terms: D020121:5' Untranslated Regions; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D017930:Genes, Reporter; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D005983:Glutens / Q000235:genetics* / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012639:Seeds / Q000235:genetics* / Q000378:metabolism
chemical_list: D020121:5' Untranslated Regions; D005983:Glutens; D005966:Glucuronidase