1
|
Feng J, Xu Y, Lin P, Peng X, Wang Y, Zhang Z. Identification of IκBα in Japanese eel Anguilla japonica that impairs the IKKα-dependent activation of NF-κB, AP1, and type I IFN signaling pathways. Dev Comp Immunol 2021; 122:104044. [PMID: 33915176 DOI: 10.1016/j.dci.2021.104044] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/08/2021] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
As a member of inhibitory κB family (IκB) family, IκBα is best-characterized and plays a central negative feedback regulator of NF-κB pathway in mammals, but the information about IκBα in the regulation of immune responses is still limited in teleost fishes. In the present study, the full-length cDNA of an IκBα homologue, AjIκBα, was cloned by 5' and 3' SMART RACE from Japanese eel, and its characteristics of expression in response to various PAMPs and A. hydrophila infection were investigated both in vivo and in vitro using quantitative real-time polymerase chain reaction (qRT-PCR). In addition, the subcellular localization of AjIκBα GFP fusion protein and the induction of AjIκBα alone or co-expression with Japanese eel IKKα (AjIKKα) in the activation of NF-κB, type I IFN and AP1 performed using Dual-Glo luciferase assay system were also detected. Sequence comparison analysis revealed that AjIκBα has typical conserved domains, including the N-terminal conserved degradation motif, the ankyrin repeats, and the C-terminal PEST domain. The predicted three-dimensional structure of AjIκBα is similar to that of human IκBα. qRT-PCR analysis revealed a broad expression for AjIκBα in a wide range of tissues, with the highest expression in the spleen, followed by intestine, liver, gills, skin, kidney, and with a lower expression in the heart and muscle. The AjIκBα expressions in the kidney, spleen, and especially in liver were significantly induced following injection with Gram-negative bacterial component LPS, the viral mimic poly I:C and Aeromonas hydrophila infection. In vitro, the AjIκBα transcripts of Japanese eel liver cells were significantly enhanced by the treatment of LPS, poly I:C, or the stimulation of different concentration of Aeromonas hydrophil. Luciferase assays demonstrated that not only could the AjIκBα expression significantly decrease the activation of NF-κB, AP1, and IFNβ-responsive promoters in HEK293 cells and EPC cells, but also robustly inhibited the activity of these three promoters in HEK293 cells or NF-κB and AP1-responsive promoters in EPC cells induced by AjIKKα. Additionally, subcellular localization studies showed that AjIκBα was evenly distributed in the cytoplasm and nucleus both in HEK293 cells and EPC cells under natural state. AjIκBα was found to aggregate into spots in the cytoplasm and nucleus stimulated by LPS or mostly aggregate into nucleus with the treatment of poly I:C in HEK293 cells, whereas the elevated expression of AjIκBα was observed in the cytoplasm of EPC cells upon the stimulation of poly I:C. These results collectively indicated that AjIκBα function as an important negative regulation in innate immunity of host against antibacterial and antiviral infection likely via the inhibition of the activation of NF-κB, AP1, and type I IFN signaling pathways.
Collapse
Affiliation(s)
- Jianjun Feng
- Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China.
| | - Yuankai Xu
- Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; Ningbo Institute of Oceanography, Ningbo, 315832, China
| | - Peng Lin
- Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China
| | - Xinwei Peng
- Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China
| | - Yilei Wang
- Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China
| | - Ziping Zhang
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| |
Collapse
|
2
|
Feng J, Xu Y, Lin P, Wang Y, Zhang Z, Zou P, Peng X. Fish IKKα from Japanese eel (Anguilla japonica) can activate NF-κB, AP1, and type I IFN signaling pathways. Fish Shellfish Immunol 2020; 106:982-992. [PMID: 32920202 DOI: 10.1016/j.fsi.2020.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/28/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
Inhibitor of nuclear factor kappa-B kinase subunit alpha (IKKα) plays a pivotal role in the activation of nuclear factor kappa-B (NF-κB) pathway in response to pathogens infections in mammals, but the information about IKKα in the regulation of immune responses is still limited in teleost fishes. In the present study, the full-length cDNA of an IKKα homologue, AjIKKα, was cloned by 5' and 3' SMART RACE from Japanese eel, and its characteristics of expression in response to various PAMPs and A. hydrophila infection were investigated both in vivo and in vitro using quantitative real-time polymerase chain reaction (qRT-PCR). In addition, the subcellular localization of AjIKKα GFP fusion protein and the induction of AjIKKα in the activation of NF-κB, type I IFN and AP1 performed using Dual-Glo luciferase assay system were also detected. Sequence comparison analysis revealed that AjIKKα has typical conserved domains, including an N-terminal kinase domain, an ubiquitin-like domain, a scaffold dimerization domain, and a C-terminal NEMO-binding domain. The predicted three-dimensional structure of AjIKKα is similar to that of human IKKα. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed a broad expression for AjIKKα in a wide range of tissues, with the highest expression in the liver, followed by the intestine, gills, and spleen, and with a lower expression in the muscle and heart. The AjIKKα expressions in the liver and kidney were significantly induced following injection with the viral mimic poly I:C and Aeromonas hydrophila infection, whereas the bacterial mimic LPS down-regulated the expression of AjIKKα in the spleen. In vitro, the AjIKKα transcripts of Japanese eel liver cells were significantly enhanced by the treatment of LPS, poly I:C, CpG-DNA, and PGN or the stimulation of different concentration of Aeromonas hydrophila (1 × 106 cfu/mL, 1 × 107 cfu/mL, and 1 × 108 cfu/mL). Luciferase assays demonstrated that AjIKKα expression could significantly induce NF-κB, AP-1 and type I IFN promoter activation in a dose-dependent manner. Additionally, subcellular localization studies showed that AjIKKα was evenly distributed in the cytoplasm in the natural state, but AjIKKα was found to aggregate into spots in the cytoplasm after the stimulation of LPS and poly I:C. These results collectively indicated that AjIKKα plays an important role in innate immunity of host against antibacterial and antiviral infection likely via the activation of NF-κB, AP1and type I IFN signaling pathway.
Collapse
Affiliation(s)
- Jianjun Feng
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China.
| | - Yuankai Xu
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China
| | - Peng Lin
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China
| | - Yilei Wang
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China
| | - Ziping Zhang
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Pengfei Zou
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China
| | - Xinwei Peng
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China
| |
Collapse
|
3
|
Liang Y, Liu H, Li X, Huang W, Huang B, Xu J, Xiong J, Zhai S. Molecular insight, expression profile and subcellular localization of two STAT family members, STAT1a and STAT2, from Japanese eel, Anguilla japonica. Gene 2020; 769:145257. [PMID: 33164823 DOI: 10.1016/j.gene.2020.145257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/15/2020] [Accepted: 10/20/2020] [Indexed: 12/14/2022]
Abstract
Signal transducer and activator of transcription 1 (STAT1) and STAT2 are critical components of type I and type II IFNs signaling. To date, seven STAT family proteins have been identified from mammals. However, the information on STAT genes in teleost fish is still limited. In the present study, two STAT family genes (STAT1a and STAT2) were identified from Japanese eel, Anguilla japonica and designated as AjSTAT1a and AjSTAT2. The open reading frames of AjSTAT1a and AjSTAT2 are 2244 bp and 2421 bp, encoding for polypeptides of 747 aa and 806 aa, respectively. Both AjSTAT1a and AjSTAT2 contain the conserved domains of STAT proteins. Phylogenetic analysis was performed based on the STATs protein sequences, and showed that AjSTAT1a and AjSTAT2 shared the closest relationship with Oncorhynchus mykiss. Quantitative real-time PCR analysis revealed that AjSTAT1a and AjSTAT2 were expressed in most examined tissues, with the highest expression both in blood. Significantly up-regulated transcripts of AjSTAT1a and AjSTAT2 were detected in response to poly I:C stimulation, and Edwardsiella tarda induced increase in the expression of AjSTAT1a and AjSTAT2 genes. Subcellular localization analysis showed that in both IFNγ-stimulated and unstimulated EPC cells AjSTAT1a and AjSTAT2 were mainly distributed in the cytoplasm, but few AjSTAT1a was distributed in the nucleus. All these results suggested that AjSTAT1a and AjSTAT2 may be critical for regulating the host innate immune defense against pathogens invasion.
Collapse
Affiliation(s)
- Ying Liang
- Fisheries College, Jimei University, Xiamen 361021, China; Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture, Xiamen 361021, China; Key Laboratory of Cultivation and High-value Utilization of Marine Organisms in Fujian Province, Xiamen 361000, China; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, P.R. China, Xiamen 361021, China.
| | - Haizi Liu
- Fisheries College, Jimei University, Xiamen 361021, China
| | - Xiang Li
- Fisheries College, Jimei University, Xiamen 361021, China
| | - Wenshu Huang
- Fisheries College, Jimei University, Xiamen 361021, China; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, P.R. China, Xiamen 361021, China
| | - Bei Huang
- Fisheries College, Jimei University, Xiamen 361021, China; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, P.R. China, Xiamen 361021, China
| | - Jisong Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, P.R. China, Xiamen 361021, China
| | - Jing Xiong
- Fisheries College, Jimei University, Xiamen 361021, China; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, P.R. China, Xiamen 361021, China
| | - Shaowei Zhai
- Fisheries College, Jimei University, Xiamen 361021, China; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, P.R. China, Xiamen 361021, China
| |
Collapse
|
4
|
Feng J, Lin P, Wang Y, Zhang Z. Molecular characterization, expression patterns, and functional analysis of toll-interacting protein (Tollip) in Japanese eel Anguilla japonica. Fish Shellfish Immunol 2019; 90:52-64. [PMID: 31015066 DOI: 10.1016/j.fsi.2019.04.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/18/2019] [Accepted: 04/19/2019] [Indexed: 06/09/2023]
Abstract
Toll-interacting protein (Tollip) is a key negative regulator of TLR-mediated innate immune responses. The structure and function of Tollip have been well identified in mammals, but the information about Tollip is still limited in teleost fishes. In the present study, the homologue of Tollip was cloned from Japanese eel. It contained an open reading frame encoding a polypeptide of 276 amino acids which shared high identities with other homologues from different species. Multiple alignment of the amino acid sequence showed that the AjTollip protein has the typical conserved domains including an N-terminal Target of Myb1 (Tom1) binding domain (TBD), a central conserved 2 (C2) domain, and a C-terminal coupling of ubiquitin to endoplasmic reticulum degradation (CUE) domain. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed a broad expression for AjTollip in a wide range of tissues, with the highest expression in the liver, a relatively high expression in the spleen, kidney, gills, skin and intestine, and a low expression in the heart and muscle. The AjTollip expressions in the liver and kidney were significantly induced following injection with the bacterial mimic LPS, the viral mimic poly I:C, and Aeromonas hydrophila infection. In vitro, the AjTollip transcripts of Japanese eel liver cells were significantly enhanced by the treatment of LPS, poly I:C, CpG-DNA, and PGN or the stimulation of high concentration of Aeromonas hydrophila (1 × 107 cfu/mL and 1 × 108 cfu/mL). Subcellular localization study showed that AjTollip was mainly distributed in the cytoplasm in a condensed state. When AjTollip was co-transfected with AjMyD88 into HEK293 cells, the luciferase activities of NF-κB were significantly decreased compared with that of AjMyD88 single-transfection groups in natural state or under the stimulation of LPS and poly I:C. These results collectively suggested that AjTollip functions as a negative regulator of MyD88-dependent TLR signaling and plays an important role in fish defense against viral and bacterial infections.
Collapse
Affiliation(s)
- Jianjun Feng
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China.
| | - Peng Lin
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China
| | - Yilei Wang
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China
| | - Ziping Zhang
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| |
Collapse
|
5
|
Wang T, Lin P, Guo S, Wang Y, Zhang Z, Feng J. Molecular characterization and expression analysis of signal transducer and activator of transcription 1 (STAT1) in Japanese eel Anguilla japonica. Fish Shellfish Immunol 2019; 86:956-964. [PMID: 30590158 DOI: 10.1016/j.fsi.2018.12.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 12/20/2018] [Accepted: 12/23/2018] [Indexed: 06/09/2023]
Abstract
Signal transducer and activator of transcription 1 (STAT1) is one of critical signal transduction proteins of interferon (IFN) pathway and the structure and function of this protein have been well identified in mammals, but the information about the STAT1 is still limited in teleost fishes. In the present study, the full-length cDNA sequence of STAT1 (AjSTAT1) in Japanese eel (Anguilla japonica) was identified and characterized. Multiple alignment of the amino acid sequence showed that the AjSTAT1 protein has the typical conserved domains including the amino-terminal, coiled-coil, DNA-binding, linker, Src homology 2 (SH2), transcriptional activation domains (TAD). Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed a broad expression for AjSTAT1 in a wide range of tissues, with the predominant expression in liver, followed by the spleen, intestine, gills, skin, kidney, and the very low expression in heart and muscle. The AjSTAT1 expressions in liver, spleen and kidney were significantly induced following injection with LPS, the viral mimic poly I:C, and Aeromonas hydrophila infection. In vitro, the AjSTAT1 transcripts of Japanese eel liver cells were significantly enhanced by the treatment of poly I:C or the stimulation of the high concentration of Aeromonas hydrophila (1 × 107 cfu/mL and 1 × 108 cfu/mL). Subcellular localization showed that in the natural state AjSTAT1was uniformly distributed in the cytoplasm, but AjSTAT1 was found to aggregated in the cytoplasm as well as partly in the nucleus after the stimulation of LPS and poly I:C. These results collectively suggested AjSTAT1 is an important transcription factor possibly involved in Japanese eel defense against viral and bacterial infection.
Collapse
Affiliation(s)
- Tingting Wang
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, China
| | - Peng Lin
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, China
| | - Songlin Guo
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, China
| | - Yilei Wang
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, China
| | - Ziping Zhang
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jianjun Feng
- College of Fisheries, Jimei University, Xiamen, 361021, Fujian Province, China; Engineer Research Center of Eel Modern Industry Technology, Ministry of Education, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, China.
| |
Collapse
|
6
|
Fang P, Fang L, Liu X, Hong Y, Wang Y, Dong N, Ma P, Bi J, Wang D, Xiao S. Identification and subcellular localization of porcine deltacoronavirus accessory protein NS6. Virology 2016; 499:170-177. [PMID: 27661736 PMCID: PMC7111631 DOI: 10.1016/j.virol.2016.09.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/14/2016] [Accepted: 09/15/2016] [Indexed: 12/27/2022]
Abstract
Porcine deltacoronavirus (PDCoV) is an emerging swine enteric coronavirus. Accessory proteins are genus-specific for coronavirus, and two putative accessory proteins, NS6 and NS7, are predicted to be encoded by PDCoV; however, this remains to be confirmed experimentally. Here, we identified the leader-body junction sites of NS6 subgenomic RNA (sgRNA) and found that the actual transcription regulatory sequence (TRS) utilized by NS6 is non-canonical and is located upstream of the predicted TRS. Using the purified NS6 from an Escherichia coli expression system, we obtained two anti-NS6 monoclonal antibodies that could detect the predicted NS6 in cells infected with PDCoV or transfected with NS6-expressing plasmids. Further studies revealed that NS6 is always localized in the cytoplasm of PDCoV-infected cells, mainly co-localizing with the endoplasmic reticulum (ER) and ER-Golgi intermediate compartments, as well as partially with the Golgi apparatus. Together, our results identify the NS6 sgRNA and demonstrate its expression in PDCoV-infected cells.
Collapse
Affiliation(s)
- Puxian Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Liurong Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Xiaorong Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Yingying Hong
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Yongle Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Nan Dong
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Panpan Ma
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Jing Bi
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; Department of Immunology and Aetology, College of Basic Medicine, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Dang Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Shaobo Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China.
| |
Collapse
|