title: Presence of Tube isoforms in Litopenaeus vannamei suggests various regulatory patterns of signal transduction in invertebrate NF-κB pathway.
abstract: The toll-like receptor (TLR)/NF-κB signaling pathways play critical roles in the innate immune system. The intracellular signal transduction of most TLR pathways in invertebrate cells is triggered by formation of a heterotrimeric complex composed of MyD88, Tube and Pelle. In this study, we identified a Litopenaeus vannamei Pelle (LvPelle) and an isoform of L. vannamei Tube (LvTube) designated as LvTube-1. The interactions among LvPelle, LvTube/LvTube-1 and LvMyD88/LvMyD88-1 were elucidated and their functions during pathogen infections were investigated. Knockdowns of LvPelle and LvTube/LvTube-1 using RNAi strategy led to higher mortalities of shrimps during Vibrio parahemolyticus infection, and could reduce the genome copy number of white spot syndrome virus (WSSV) in the infected muscle tissue but did not affect the mortality caused by WSSV infection. The effects of LvPelle and LvTube/LvTube-1 on promoters containing NF-κB binding motifs were analyzed by dual-luciferase reporter assays and the results demonstrated that LvTube-1 could activate the NF-κB activity to significantly higher level than LvTube did. Moreover, tissue distributions of LvTube and LvTube-1 mRNAs and their expression profiles during pathogen and immune stimulant challenges were different, indicating that they could play different roles in immune responses. This is the first report of Tube isoforms in invertebrates. Together with our previous study on LvMyD88 isoforms, our results suggest that various isoforms of adaptor components may be involved in various regulatory patterns of signal transduction in invertebrate TLR/NF-κB pathway and this could be a strategy adopted by invertebrates to modulate immune responses.
authors.affiliation: MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Chaozheng
authors.initials: C
authors.lastname: Li
authors.forename: Yixiao
authors.initials: Y
authors.lastname: Chen
authors.forename: Shaoping
authors.initials: S
authors.lastname: Weng
authors.forename: Sedong
authors.initials: S
authors.lastname: Li
authors.forename: Hongliang
authors.initials: H
authors.lastname: Zuo
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Yu
authors.forename: Haoyang
authors.initials: H
authors.lastname: Li
authors.forename: Jianguo
authors.initials: J
authors.lastname: He
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Xu
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D003001:Cloning, Molecular; D004266:DNA Virus Infections / Q000276:immunology*; D008969:Molecular Sequence Data; D053594:Myeloid Differentiation Factor 88 / Q000276:immunology; D016328:NF-kappa B / Q000276:immunology*; D033561:Penaeidae / Q000276:immunology* / Q000382:microbiology; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000276:immunology; D034622:RNA Interference; D034741:RNA, Small Interfering; D016415:Sequence Alignment; D015398:Signal Transduction; D014735:Vibrio Infections / Q000276:immunology*; D014736:Vibrio parahaemolyticus / Q000276:immunology; D046848:White spot syndrome virus 1 / Q000276:immunology
chemical_list: D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D020033:Protein Isoforms; D034741:RNA, Small Interfering
keywords: Litopenaeus vannamei; LvPell; LvTube; LvTube-1; Toll-like receptor (TLR)/NF-κB signaling pathway