文献类型：期刊文献

英文题名：Revisiting the functions of periplasmic chaperones in the quality control of the autotransporter Ag43 using a phenotypically homogeneous Escherichia coli strain

作者：Xue, Zixiao[1];Pang, Yonghao[1];Quan, Shu[1,2]

机构：[1]East China Univ Sci & Technol, Shanghai Collaborat Innovat Ctr Biomfg SCICB, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Shanghai Frontiers Sci Ctr Optogenet Tech Cell Me, Shanghai 200237, Peoples R China

年份：2022

卷号：591

起止页码：37

外文期刊名：BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000742671900001)】；

基金：We thank James C. A. Bardwell (University of Michigan) and Zhen Yan (University of Michigan) for helpful suggestions and the primary antibodies of Ag43. This work was supported by National Natural Science Founda-tion of China (NSFC) grants 31661143021 and 32171269 (to S.Q.) , the Fundamental Research Funds for the Central Universities (grant 22221818014 to S.Q.) , the Research Program of State Key Laboratory of Bioreactor Engineering (to S.Q.), and a grant from Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism (Shanghai Municipal Education Commission, grant 2021 Sci & Tech 03-28).

语种：英文

外文关键词：Autotransporter; Ag43; Phase variation; Molecular chaperone; Protein quality control; SurA; OsmY

摘要：Antigen 43 is a surface-displayed autotransporter protein that mediates bacterial self-association and pathogenicity. The quality control factors that facilitate Ag43 crossing the periplasm and inserting into the outer membrane remain enigmatic, mostly because Ag43 is phase variable and associated with heterologous phenotypes, which obscures the mutational effects of potential quality control factors. Here, we describe a screening method that allowed us to isolate a subpopulation of Escherichia coli that consistently displays an Ag43-mediated autoaggregation phenotype. Based on this subpopulation, we analyzed how disruptions of known periplasmic chaperones affect Ag43 biogenesis. We found that only the disruption of surA reduced Ag43 levels and abolished the autoaggregation phenotype of cells, but surA disruption did not affect the phase-variable expression of agn43. Using purified proteins, we showed that SurA effectively protected the I3-barrel domain of Ag43 from aggregation. In contrast, the previously reported Ag43 biogenesis factor OsmY showed weak chaperoning effects on Ag43 only in the absence of SurA. Our results shed light on the roles of different periplasmic chaperones in Ag43 biogenesis and provide a methodology applicable to the study of other phase-variable proteins. (c) 2021 Elsevier Inc. All rights reserved.