Yersinia pseudotuberculosis YopD mutants that genetically separate effector protein translocation from host membrane disruption |
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| Authors: | Walter Adams Jessica Morgan Laura Kwuan Victoria Auerbuch |
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| Affiliation: | 1. Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA, USA;2. Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA, USA |
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| Abstract: | The Yersinia type III secretion system (T3SS) translocates Yop effector proteins into host cells to manipulate immune defenses such as phagocytosis and reactive oxygen species (ROS) production. The T3SS translocator proteins YopB and YopD form pores in host membranes, facilitating Yop translocation. While the YopD amino and carboxy termini participate in pore formation, the role of the YopD central region between amino acids 150–227 remains unknown. We assessed the contribution of this region by generating Y. pseudotuberculosis yopDΔ150–170 and yopDΔ207–227 mutants and analyzing their T3SS functions. These strains exhibited wild‐type levels of Yop secretion in vitro and enabled robust pore formation in macrophages. However, the yopDΔ150–170 and yopDΔ207–227 mutants were defective in Yop translocation into CHO cells and splenocyte‐derived neutrophils and macrophages. These data suggest that YopD‐mediated host membrane disruption and effector Yop translocation are genetically separable activities requiring distinct protein domains. Importantly, the yopDΔ150–170 and yopDΔ207–227 mutants were defective in Yop‐mediated inhibition of macrophage cell death and ROS production in neutrophil‐like cells, and were attenuated in disseminated Yersinia infection. Therefore, the ability of the YopD central region to facilitate optimal effector protein delivery into phagocytes, and therefore robust effector Yop function, is important for Yersinia virulence. |
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