title: Identification and functional analysis of a TEP gene from a crustacean reveals its transcriptional regulation mediated by NF-κB and JNK pathways and its broad protective roles against multiple pathogens.
abstract: Thioester-containing proteins (TEPs) are present in a wide range of species from deuterostomes to protostomes and are thought to be involved in innate immunity. In the current study, a TEP gene homologous to insect TEPs (iTEP) from the crustacean Litopenaeus vannamei, named LvTEP1, is cloned and functionally characterized. The open reading frame (ORF) of LvTEP1 is 4383 bp in length, encoding a polypeptide of 1460 amino acids with a calculated molecular weight of 161.1 kDa LvTEP1, which is most similar to other TEPs from insects, contains some conserved sequence features, including a N-terminal signal peptide, a canonical thioester (TE) motif, and a C-terminal distinctive cysteine signature. LvTEP1 is expressed in most immune-related tissues, such as intestine, epithelium, and hemocytes, and the mRNA level of LvTEP1 is upregulated in hemocytes after bacterial and viral challenges, indicating its involvement in the shrimp innate immune response. An expression assay in Drosophila S2 cells shows LvTEP1 to be a full-length secretory protein, and processed forms are present in the supernatant. Of note, only the processed form of LvTEP1 protein can bind to both the gram-negative bacterium Vibrio parahaemolyticus and the gram-positive bacterium Staphylococcus aureus in vitro, and its abundance can be induced after bacterial treatment. Moreover, knockdown of LvTEP1 renders shrimps more susceptible to both V. parahaemolyticus and S. aureus, as well as white spot syndrome virus (WSSV) infection, suggesting its essential defensive role against these invading microbes. We also observe that the expression of LvTEP1 is regulated in a manner dependent on both NF-κB and AP-1 transcription factors in naive shrimps and in vitro, suggesting that LvTEP1 could be poised in the body cavity prior to infection and thus play an important role in basal immunity. Taken together, our findings provide some in vitro and in vivo evidence for the involvement of LvTEP1 in shrimp innate immunity and provide some insight into its expression regulation mediated by multiple transcription factors or signaling pathways.
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, PR China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, PR China; School of Marine Sciences, Sun Yat-sen University, Guangzhou, PR China; South China Sea Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), PR China. Electronic address: lichaozh@mail2.sysu.edu.cn.
authors.forename: Chaozheng
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, PR China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, PR China.
authors.forename: Haoyang
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, PR China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, PR China.
authors.forename: Bang
authors.initials: B
authors.lastname: Xiao
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, PR China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, PR China; School of Marine Sciences, Sun Yat-sen University, Guangzhou, PR China; South China Sea Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), PR China.
authors.forename: Yonggui
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, PR China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, PR China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, PR China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, PR China.
authors.forename: Kai
authors.initials: K
authors.lastname: Lǚ
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, PR China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yin
authors.affiliation: Fisheries Research Institute of Zhanjiang, Zhanjiang, PR China.
authors.forename: Sedong
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, PR China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, PR China; School of Marine Sciences, Sun Yat-sen University, Guangzhou, PR China; South China Sea Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), PR China. Electronic address: lsshjg@mail.sysu.edu.cn.
authors.forename: Jianguo
authors.initials: J
authors.lastname: He
mesh_terms: D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics / Q000378:metabolism*; D001424:Bacterial Infections / Q000276:immunology*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003001:Cloning, Molecular; D004266:DNA Virus Infections / Q000276:immunology*; D004330:Drosophila; D005786:Gene Expression Regulation; D006434:Hemocytes / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D007113:Immunity, Innate; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D033561:Penaeidae / Q000276:immunology*; D034741:RNA, Small Interfering / Q000235:genetics; D016601:RNA-Binding Proteins; D015398:Signal Transduction; D013211:Staphylococcus aureus / Q000276:immunology*; D014736:Vibrio parahaemolyticus / Q000276:immunology*; D046848:White spot syndrome virus 1 / Q000276:immunology*
chemical_list: D060829:Arthropod Proteins; D002352:Carrier Proteins; D016328:NF-kappa B; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; C498415:Tep1 protein, mouse; D048031:JNK Mitogen-Activated Protein Kinases
keywords: AP-1; Innate immunity; Litopenaeus vannamei; NF-κB; Thioester-containing protein