title: Molecular cloning, characterization and function of a germinal center kinase MST4 gene from Litopenaeus vannamei in response to Vibrio alginolyticus challenge in TLR-TRAF6 signaling pathway.
abstract: The serine/threonine protein kinase MST4 plays multiple roles in the regulation of signaling pathways that govern cellular processes including mitosis, migration, homeostasis, polarity, proliferation, differentiation and apoptosis. Here we report the identification and characterization of the full-length sequence of LvMST4 from the shrimp L. vannamei, and investigations into its role in the shrimp's immune response to infection by the pathogenic bacterium Vibrio alginolyticus. Subcellular localization assays demonstrated the enzyme's presence in the shrimp's cytoplasm, and tissue-specific expression analysis revealed that it is expressed ubiquitously but at different levels in different tissues. Infection with V. alginolyticus increased LvMST4 expression and induced a rapid response via the TLR-TRAF6 signaling pathway, causing a decline in the total hemocyte count (THC) and an increase in respiratory burst (RB) activity. In non-infected shrimp, RNAi silencing of LvMST4 with dsRNA had no significant effect on THC but seemed to activate the TRAF6-MKK6-p38 pathway and reduced RB activity. In shrimp challenged with V. alginolyticus, LvMST4 silencing reduced bacterial clearance and increased the initial upregulation of LvTRAF6 while reducing the expression of LvMKK6 and Lvp38. LvMST4 silencing also slightly reduced the THC but caused pronounced increases in RB activity and cumulative mortality. These findings suggest that LvMST4 contributes to antimicrobial responses via the TLR-TRAF6 signal pathway, and helps maintain immunological homeostasis in L. vannamei.
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors.forename: Chang-Sheng
authors.initials: CS
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors.forename: Di
authors.initials: D
authors.lastname: Huang
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Peng
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors.forename: Ming-Zhu
authors.initials: MZ
authors.lastname: Huang
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors.forename: Chen-Ying
authors.initials: CY
authors.lastname: Xie
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors.forename: Jing-Rong
authors.initials: JR
authors.lastname: Kong
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors.forename: Ren-Chong
authors.initials: RC
authors.lastname: Xie
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China. Electronic address: wangwn@scnu.edu.cn.
authors.forename: Wei-Na
authors.initials: WN
authors.lastname: Wang
mesh_terms: D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics / Q000276:immunology*; D000081410:Germinal Center Kinases; D007113:Immunity, Innate / Q000235:genetics / Q000276:immunology; D033561:Penaeidae / Q000235:genetics / Q000276:immunology*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000276:immunology*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D048029:TNF Receptor-Associated Factor 6 / Q000276:immunology; D051193:Toll-Like Receptors / Q000235:genetics / Q000276:immunology; D014735:Vibrio Infections / Q000662:veterinary; D044149:Vibrio alginolyticus / Q000276:immunology
chemical_list: D060829:Arthropod Proteins; D000081410:Germinal Center Kinases; D048029:TNF Receptor-Associated Factor 6; D051193:Toll-Like Receptors; D017346:Protein Serine-Threonine Kinases
keywords: Immunologic homeostasis; LvMST4; RNAi; TLR-TRAF6 signal pathway; Vibrio alginolyticus challenge