title: Production of human growth hormone in transgenic rice seeds: co-introduction of RNA interference cassette for suppressing the gene expression of endogenous storage proteins.
abstract: Rice seeds are potentially useful hosts for the production of pharmaceutical proteins. However, low yields of recombinant proteins have been observed in many cases because recombinant proteins compete with endogenous storage proteins. Therefore, we attempt to suppress endogenous seed storage proteins by RNA interference (RNAi) to develop rice seeds as a more efficient protein expression system. In this study, human growth hormone (hGH) was expressed in transgenic rice seeds using an endosperm-specific promoter from a 10 kDa rice prolamin gene. In addition, an RNAi cassette for reduction of endogenous storage protein expressions was inserted into the hGH expression construct. Using this system, the expression levels of 13 kDa prolamin and glutelin were effectively suppressed and hGH polypeptides accumulated to 470 μg/g dry weight at the maximum level in transgenic rice seeds. These results suggest that the suppression of endogenous protein gene expression by RNAi could be of great utility for increasing transgene products.
authors: Laboratory of Genetic Engineering, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan.
authors: Takanari
authors: T
authors: Shigemitsu
authors: Shinji
authors: S
authors: Ozaki
authors: Yuhi
authors: Y
authors: Saito
authors: Masaharu
authors: M
authors: Kuroda
authors: Shigeto
authors: S
authors: Morita
authors: Shigeru
authors: S
authors: Satoh
authors: Takehiro
authors: T
authors: Masumura
mesh_terms: D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D005983:Glutens / Q000235:genetics / Q000378:metabolism; D013006:Growth Hormone / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009928:Organ Specificity; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D030821:Plants, Genetically Modified; D055315:Prolamins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D021382:Protein Sorting Signals; D021381:Protein Transport; D034622:RNA Interference; D055314:Seed Storage Proteins / Q000235:genetics / Q000378:metabolism*; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D019076:Transgenes
chemical_list: D055315:Prolamins; D021382:Protein Sorting Signals; D055314:Seed Storage Proteins; D005983:Glutens; D013006:Growth Hormone