[Leung, Ka Yin] Trinity Western Univ, Fac Nat & Appl Sci, Dept Biol, Langley, BC V2Y 1Y1, Canada; [Xie, Hai Xia; Zheng, Jun; Mok, Yu-Keung; Leung, Ka Yin] Natl Univ Singapore, Fac Sci, Dept Biol Sci, Singapore 117543, Singapore; [Xie, Hai Xia; Nie, Pin] Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Hubei Province, Peoples R China; [Yu, Hong Bing; Finlay, B. Brett] Univ British Columbia, Michael Smith Labs, Vancouver, BC V6T 1Z4, Canada; [Foster, Leonard J.] Univ British Columbia, Ctr High Throughput Biol, Dept Biochem & Mol Biol, Vancouver, BC V6T 1Z4, Canada
WOS标题词:
Science & Technology
; Life Sciences & Biomedicine
Edwardsiella tarda is a Gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and both gastrointestinal and extraintestinal infections in humans. A type III secretion system (T3SS) was recently shown to contribute to pathogenesis, since deletions of various T3SS genes increased the 50% lethal dose (LD50) by about 1 log unit in the blue gourami infection model. In this study, we report EseG as the first identified effector protein of T3SS. EseG shares partial homology with two Salmonella T3SS effectors (SseG and SseF) over a conserved domain (amino acid residues 142 to 192). The secretion of EseG is dependent on a functional T3SS and, in particular, requires the chaperone EscB. Experiments using TEM-1 beta-lactamase as a fluorescence-based reporter showed that EseG was translocated into HeLa cells at 35 degrees C. Fractionation of infected HeLa cells demonstrated that EseG was localized to the host membrane fraction after translocation. EseG is able to disassemble microtubule structures when overexpressed in mammalian cells. This phenotype may require a conserved motif of EseG (EseG(142-192)), since truncated versions of EseG devoid of this motif lose their ability to cause microtubule destabilization. By demonstrating the function of EseG, our study contributes to the understanding of E. tarda pathogenesis. Moreover, the approach established in this study to identify type III effectors can be used to identify and characterize more type III and possible type VI effectors in Edwardsiella.
英文摘要:
Edwardsiella tarda is a Gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and both gastrointestinal and extraintestinal infections in humans. A type III secretion system (T3SS) was recently shown to contribute to pathogenesis, since deletions of various T3SS genes increased the 50% lethal dose (LD(50)) by about 1 log unit in the blue gourami infection model. In this study, we report EseG as the first identified effector protein of T3SS. EseG shares partial homology with two Salmonella T3SS effectors (SseG and SseF) over a conserved domain (amino acid residues 142 to 192). The secretion of EseG is dependent on a functional T3SS and, in particular, requires the chaperone EscB. Experiments using TEM-1 beta-lactamase as a fluorescence-based reporter showed that EseG was translocated into HeLa cells at 35 degrees C. Fractionation of infected HeLa cells demonstrated that EseG was localized to the host membrane fraction after translocation. EseG is able to disassemble microtubule structures when overexpressed in mammalian cells. This phenotype may require a conserved motif of EseG (EseG(142-192)), since truncated versions of EseG devoid of this motif lose their ability to cause microtubule destabilization. By demonstrating the function of EseG, our study contributes to the understanding of E. tarda pathogenesis. Moreover, the approach established in this study to identify type III effectors can be used to identify and characterize more type III and possible type VI effectors in Edwardsiella.
1.Trinity Western Univ, Fac Nat & Appl Sci, Dept Biol, Langley, BC V2Y 1Y1, Canada 2.Natl Univ Singapore, Fac Sci, Dept Biol Sci, Singapore 117543, Singapore 3.Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Hubei Province, Peoples R China 4.Univ British Columbia, Michael Smith Labs, Vancouver, BC V6T 1Z4, Canada 5.Univ British Columbia, Ctr High Throughput Biol, Dept Biochem & Mol Biol, Vancouver, BC V6T 1Z4, Canada
Recommended Citation:
Xie, Hai Xia; Yu, Hong Bing; Zheng, Jun; Nie, Pin; Foster, Leonard J.; Mok, Yu-Keung; Finlay, B. Brett; Leung, Ka Yin.EseG, an Effector of the Type III Secretion System of Edwardsiella tarda, Triggers Microtubule Destabilization,INFECTION AND IMMUNITY,2010,78(12):5011-5021
