title: High yield exogenous protein HPL production in the Bombyx mori silk gland provides novel insight into recombinant expression systems.
abstract: The silk gland of Bombyx mori (BmSG) has gained significant attention by dint of superior synthesis and secretion of proteins. However, the application of BmSG bioreactor is still a controversial issue because of low yields of recombinant proteins. Here, a 3057 bp full-length coding sequence of Hpl was designed and transformed into the silkworm genome, and then the mutant (Hpl/Hpl) with specific expression of Hpl in posterior BmSG (BmPSG) was obtained. In the mutants, the transcription level of Fib-L and P25, and corresponding encoding proteins, did not decrease. However, the mRNA level of Fib-H was reduced by 71.1%, and Fib-H protein in the secreted fibroin was decreased from 91.86% to 71.01%. The mRNA level of Hpl was 0.73% and 0.74% of Fib-H and Fib-L, respectively, while HPL protein accounted for 18.85% of fibroin and 15.46% of the total amount of secreted silk protein. The exogenous protein was therefore very efficiently translated and secreted. Further analysis of differentially expressed gene (DEG) was carried out in the BmPSG cells and 891 DEGs were detected, of which 208 genes were related to protein metabolism. Reduced expression of endogenous silk proteins in the BmPSG could effectively improve the production efficiency of recombinant exogenous proteins.
authors.affiliation: School of Biology and Basic Medical Sciences, Medical College, Soochow University, Suzhou 215123, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
authors.affiliation: School of Biology and Basic Medical Sciences, Medical College, Soochow University, Suzhou 215123, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.affiliation: School of Biology and Basic Medical Sciences, Medical College, Soochow University, Suzhou 215123, China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Biology and Basic Medical Sciences, Medical College, Soochow University, Suzhou 215123, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Tao
authors.affiliation: School of Biology and Basic Medical Sciences, Medical College, Soochow University, Suzhou 215123, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Yin
authors.affiliation: School of Biology and Basic Medical Sciences, Medical College, Soochow University, Suzhou 215123, China.
authors.forename: Yanghu
authors.initials: Y
authors.lastname: SiMa
authors.affiliation: R&D Division, Okamoto Corporation, Nara 635-8550, Japan.
authors.forename: Yujun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Biology and Basic Medical Sciences, Medical College, Soochow University, Suzhou 215123, China.|National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123, China.
authors.forename: Shiqing
authors.initials: S
authors.lastname: Xu
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D012831:Bombyx / Q000235:genetics* / Q000378:metabolism*; D019295:Computational Biology / Q000379:methods; D015870:Gene Expression; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D005822:Genetic Vectors / Q000235:genetics; D019476:Insect Proteins / Q000096:biosynthesis* / Q000235:genetics*; D009154:Mutation; D010641:Phenotype; D011994:Recombinant Proteins; D047011:Silk / Q000096:biosynthesis*
chemical_list: D019476:Insect Proteins; D011994:Recombinant Proteins; D047011:Silk