title: Increasing the yield of middle silk gland expression system through transgenic knock-down of endogenous sericin-1.
abstract: Various genetically modified bioreactor systems have been developed to meet the increasing demands of recombinant proteins. Silk gland of Bombyx mori holds great potential to be a cost-effective bioreactor for commercial-scale production of recombinant proteins. However, the actual yields of proteins obtained from the current silk gland expression systems are too low for the proteins to be dissolved and purified in a large scale. Here, we proposed a strategy that reducing endogenous sericin proteins would increase the expression yield of foreign proteins. Using transgenic RNA interference, we successfully reduced the expression of BmSer1 to 50%. A total 26 transgenic lines expressing Discosoma sp. red fluorescent protein (DsRed) in the middle silk gland (MSG) under the control of BmSer1 promoter were established to analyze the expression of recombinant. qRT-PCR and western blotting showed that in BmSer1 knock-down lines, the expression of DsRed had significantly increased both at mRNA and protein levels. We did an additional analysis of DsRed/BmSer1 distribution in cocoon and effect of DsRed protein accumulation on the silk fiber formation process. This study describes not only a novel method to enhance recombinant protein expression in MSG bioreactor, but also a strategy to optimize other bioreactor systems.
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.|Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, 2, Tiansheng Road, Beibei, Chongqing, 400716, China.
authors.forename: Sanyuan
authors.initials: S
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.
authors.forename: Le
authors.initials: L
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.
authors.forename: Run
authors.initials: R
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.
authors.forename: Jiasong
authors.initials: J
authors.lastname: Chang
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China.|Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, 2, Tiansheng Road, Beibei, Chongqing, 400716, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, People's Republic of China. xiaqy@swu.edu.cn.|Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, 2, Tiansheng Road, Beibei, Chongqing, 400716, China. xiaqy@swu.edu.cn.
authors.forename: Qingyou
authors.initials: Q
authors.lastname: Xia
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D019149:Bioreactors; D012831:Bombyx / Q000235:genetics* / Q000378:metabolism*; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics; D047030:Sericins / Q000235:genetics*; D047011:Silk / Q000096:biosynthesis* / Q000235:genetics; D000097573:Red Fluorescent Protein
chemical_list: D008164:Luminescent Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D047030:Sericins; D047011:Silk; D000097573:Red Fluorescent Protein
keywords: Bioreactor; Knock down; MSG; Sericin-1 expression system; Transgenic silkworm