title: Enhancing ergosterol production in Pichia pastoris GS115 by overexpressing squalene synthase gene from Glycyrrhiza uralensis.
abstract: The present study was designed to determine the effects of copy number variations (CNVs) of squalene synthase 1(SQS1) gene on the mevalonate (MVA) pathway. SQS1 gene from G. uralensis (GuSQS1) was cloned and over-expressed in Pichia pastoris GS115. Six recombinant P. pastoris strains containing different copy number of GuSQS1 were constructed. HPLC was used to assay the level of ergosterol in all transgenic P. pastoris strains containing GuSQS1. HPLC analysis showed that the contents of ergosterol in all of the transgenic P. pastoris containing GuSQS1 were higher than that in the negative control. And with the increase of copy number of GuSQS1, the content of ergosterol showed an increasing-decreasing-increasing pattern. The contents of ergosterol in 10-copy-GuSQS1 P. pastoris and 47-copy-GuSQS1 P. pastoris were significantly higher than that in the rest recombinant P. pastoris strains. In conclusion, the CNVs of GuSQS1 influence the content of secondary metabolites in the MVA pathway. The present study provides a basis for over-expressing GuSQS1 and increasing the content of glycyrrhizin in G. uralensis cultivars.
authors.affiliation: School of Chinese Pharmacy, Beijing University of Chinese Medicine, Beijing 100102, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Chinese Pharmacy, Beijing University of Chinese Medicine, Beijing 100102, China.
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Zhu
authors.affiliation: Beijing Institute for Drug Control, Beijing 100035, China.
authors.forename: Wen-Dong
authors.initials: WD
authors.lastname: Li
authors.affiliation: School of Chinese Pharmacy, Beijing University of Chinese Medicine, Beijing 100102, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wen
authors.affiliation: School of Chinese Pharmacy, Beijing University of Chinese Medicine, Beijing 100102, China. Electronic address: max_liucs@263.net.
authors.forename: Chun-Sheng
authors.initials: CS
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D056915:DNA Copy Number Variations / Q000235:genetics; D004875:Ergosterol / Q000096:biosynthesis*; D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000235:genetics*; D029882:Glycyrrhiza uralensis / Q000235:genetics*; D008798:Mevalonic Acid / Q000378:metabolism; D010843:Pichia / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D013186:Farnesyl-Diphosphate Farnesyltransferase; D008798:Mevalonic Acid; D004875:Ergosterol
keywords: Copy number variations; Glycyrrhiza uralensis; GuSQS1; Over-expression; Pichia pastoris