HtrA-mediated E-cadherin cleavage is limited to DegP and DegQ homologs expressed by gram-negative pathogens

Cell Communication and Signaling

Research

Silja Wessler¹  Maria Schubert¹  Carmen M. Abfalter¹  Camilla Götz¹  Gernot Posselt¹  Thomas P. Schmidt¹ 

[1] Division of Microbiology, Department of Molecular Biology, Paris-Lodron University of Salzburg, Billroth Str. 11, A-5020, Salzburg, Austria;

关键词: HtrA;    DegP;    DegQ;    E-cadherin;   

DOI  :  10.1186/s12964-016-0153-y

 received in 2016-08-09, accepted in 2016-12-01,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundThe serine proteases HtrA/DegP secreted by the human gastrointestinal pathogens Helicobacter pylori (H. pylori) and Campylobacter jejuni (C. jejuni) cleave the mammalian cell adhesion protein E-cadherin to open intercellular adhesions. A wide range of bacteria also expresses the HtrA/DegP homologs DegQ and/or DegS, which significantly differ in structure and function.MethodsE-cadherin shedding was investigated in infection experiments with the Gram-negative pathogens H. pylori, enteropathogenic Escherichia coli (EPEC), Salmonella enterica subsp. Enterica (S. Typhimurium), Yersinia enterocolitica (Y. enterocolitica), and Proteus mirabilis (P. mirabilis), which express different combinations of HtrAs. Annotated wild-type htrA/degP, degQ and degS genes were cloned and proteolytically inactive mutants were generated by a serine—to—alanine exchange in the active center. All HtrA variants were overexpressed and purified to compare their proteolytic activities in casein zymography and in vitro E-cadherin cleavage experiments.ResultsInfection of epithelial cells resulted in a strong E-cadherin ectodomain shedding as reflected by the loss of full length E-cadherin in whole cell lysates and formation of the soluble 90 kDa extracellular domain of E-cadherin (NTF) in the supernatants of infected cells. Importantly, comparing the caseinolytic and E-cadherin cleavage activities of HtrA/DegP, DegQ and DegS proteins revealed that DegP and DegQ homologs from H. pylori, S. Typhimurium, Y. enterocolitica, EPEC and P. mirabilis, but not activated DegS, cleaved E-cadherin as a substrate in vitro.ConclusionsThese data indicate that E-cadherin cleavage is confined to HtrA/DegP and DegQ proteins representing an important prevalent step in bacterial pathogenesis.

【 授权许可】

CC BY   
© The Author(s). 2016