Analysis of unfolded protein response during single-chain antibody expression in Saccaromyces cerevisiae reveals different roles for BiP and PDI in folding.
Analysis of unfolded protein response during single-chain antibody expression in Saccaromyces cerevisiae reveals different roles for BiP and PDI in folding.
复制标题
对酿酒酵母单链抗体表达过程中未折叠蛋白反应的分析揭示了 BiP 和 PDI 在折叠中的不同作用。
DOI：
10.1016/j.ymben.2005.04.002
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发表时间：
2005
影响因子：
8.4
通讯作者：
Robinson,AnneSkaja
中科院分区：
文献类型：
--
作者：
Xu,Ping;Raden,David;Doyle3rd,FrancisJ;Robinson,AnneSkaja
The production of recombinant proteins is a critical technology for biotechnology and biomedical research. Heterologous expression of secreted proteins can saturate the cell's capacity to properly fold protein, initiating the unfolded protein response (UPR), and resulting in a loss of protein expression. The overexpression of chaperone binding protein (BiP) and disulfide bond isomerase (PDI) in Saccaromyces cerevisiae can effectively increase protein production levels of single-chain antibody (scFv) 4-4-20. These studies show that overexpression of BiP did not reduce the UPR activated by heterologous protein expression; however, overexpression of PDI or co-overexpression of BiP and PDI could reduce the UPR. We observed that co-overexpression of BiP and PDI led to the greatest secretion of scFv from the cell, but BiP and PDI appear to interact with the newly synthesized scFv at different stages in the folding process, as determined by pulse-chase analysis. We propose that BiP acts primarily to facilitate translocation and retain unfolded or partially folded scFv, and PDI actively folds the scFv through its functions as a catalyst, and/or an isomerase, of disulfide bonds. Free BiP is released when scFv is folded, stabilizing Ire1p, and leading to the reduced UPR.
