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Wu Q, Xing L, Du M, Huang C, Liu B, Zhou H, Liu W, Wan F, Qian W. A Genome-Wide Analysis of Serine Protease Inhibitors in Cydia pomonella Provides Insights into Their Evolution and Expression Pattern. Int J Mol Sci 2023; 24:16349. [PMID: 38003538 PMCID: PMC10671500 DOI: 10.3390/ijms242216349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 10/26/2023] [Accepted: 10/30/2023] [Indexed: 11/26/2023] Open
Abstract
Serine protease inhibitors (serpins) appear to be ubiquitous in almost all living organisms, with a conserved structure and varying functions. Serpins can modulate immune responses by negatively regulating serine protease activities strictly and precisely. The codling moth, Cydia pomonella (L.), a major invasive pest in China, can cause serious economic losses. However, knowledge of serpin genes in this insect remain largely unknown. In this study, we performed a systematic analysis of the serpin genes in C. pomonella, obtaining 26 serpins from the C. pomonella genome. Subsequently, their sequence features, evolutionary relationship, and expression pattern were characterized. Comparative analysis revealed the evolution of a number of serpin genes in Lepidoptera. Importantly, the evolutionary relationship and putative roles of serpin genes in C. pomonella were revealed. Additionally, selective pressure analysis found amino acid sites with strong evidence of positive selection. Interestingly, the serpin1 gene possessed at least six splicing isoforms with distinct reactive-center loops, and these isoforms were experimentally validated. Furthermore, we observed a subclade expansion of serpins, and these genes showed high expression in multiple tissues, suggesting their important roles in C. pomonella. Overall, this study will enrich our knowledge of the immunity of C. pomonella and help to elucidate the role of serpins in the immune response.
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Affiliation(s)
- Qiang Wu
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Longsheng Xing
- College of Life Sciences, Hebei Basic Science Center for Biotic Interactions, Institute of Life Sciences and Green Development, Hebei University, Baoding 071000, China
| | - Min Du
- Shandong Province Key Laboratory for Integrated Control of Plant Diseases and Insect Pests, Sino-Australian Joint Research Institute of Agriculture and Environmental Health, College of Plant Health & Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Cong Huang
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Bo Liu
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Hongxu Zhou
- Shandong Province Key Laboratory for Integrated Control of Plant Diseases and Insect Pests, Sino-Australian Joint Research Institute of Agriculture and Environmental Health, College of Plant Health & Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Wanxue Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fanghao Wan
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Wanqiang Qian
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
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Liu H, Xu J, Wang L, Guo P, Tang Z, Sun X, Tang X, Wang W, Wang L, Cao Y, Xia Q, Zhao P. Serpin-1a and serpin-6 regulate the Toll pathway immune homeostasis by synergistically inhibiting the Spätzle-processing enzyme CLIP2 in silkworm, Bombyx mori. PLoS Pathog 2023; 19:e1011740. [PMID: 37851691 PMCID: PMC10629668 DOI: 10.1371/journal.ppat.1011740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 11/07/2023] [Accepted: 10/07/2023] [Indexed: 10/20/2023] Open
Abstract
The Toll receptor signaling pathway is an important innate immune response of insects to pathogen infection; its extracellular signal transduction involves serine protease cascade activation. However, excessive or constitutive activation of the Toll pathway can be detrimental. Hence, the balance between activation and inhibition of the extracellular protease cascade must be tightly regulated to achieve favorable outcomes. Previous studies have shown that serpins-serine protease inhibitors-negatively regulate insect innate immunity by inhibiting extracellular protease cascade signaling. Although the roles of serpins in insect innate immunity are well described, the physiological mechanisms underlying their synergistic effects remain poorly understand. Here, we characterize the molecular mechanism by which serpin-1a and serpin-6 synergistically maintain immune homeostasis of the silkworm Toll pathway under physiological and pathological conditions. Through in vitro biochemical assays and in vivo bioassays, we demonstrate that clip-domain serine protease 2 (CLIP2), as the Toll cascade-activating terminal protease, is responsible for processing proSpätzle1 to induce the expression of antimicrobial peptides. Further biochemical and genetic analyses indicate that constitutively expressed serpin-1a and inducible serpin-6 synergistically target CLIP2 to maintain homeostasis of the silkworm Toll pathway under physiological and pathological conditions. Taken together, this study provides new insights into the precise regulation of Toll cascade activation signals in insect innate immune responses and highlights the importance and complexity of insect immune homeostasis regulation.
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Affiliation(s)
- Huawei Liu
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Jiahui Xu
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
| | - Luoling Wang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
| | - Pengchao Guo
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Zhangchen Tang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
| | - Xiaotong Sun
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
| | - Xin Tang
- Chongqing Key Laboratory of Chinese Medicine & Health Science, Chongqing Academy of Chinese Materia Medica, Chongqing College of Traditional Chinese Medicine, Chongqing, China
| | - Wei Wang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Lingyan Wang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Yang Cao
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Qingyou Xia
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
| | - Ping Zhao
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing, China
- Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Chongqing, China
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Zhang X, Zhang S, Kuang J, Sellens KA, Morejon B, Saab SA, Li M, Metto EC, An C, Culbertson CT, Osta MA, Scoglio C, Michel K. CLIPB4 Is a Central Node in the Protease Network that Regulates Humoral Immunity in Anopheles gambiae Mosquitoes. J Innate Immun 2023; 15:680-696. [PMID: 37703846 PMCID: PMC10603620 DOI: 10.1159/000533898] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 08/29/2023] [Indexed: 09/15/2023] Open
Abstract
Insect humoral immune responses are regulated in part by protease cascades, whose components circulate as zymogens in the hemolymph. In mosquitoes, these cascades consist of clip-domain serine proteases (cSPs) and/or their non-catalytic homologs, which form a complex network, whose molecular make-up is not fully understood. Using a systems biology approach, based on a co-expression network of gene family members that function in melanization and co-immunoprecipitation using the serine protease inhibitor (SRPN)2, a key negative regulator of the melanization response in mosquitoes, we identify the cSP CLIPB4 from the African malaria mosquito Anopheles gambiae as a central node in this protease network. CLIPB4 is tightly co-expressed with SRPN2 and forms protein complexes with SRPN2 in the hemolymph of immune-challenged female mosquitoes. Genetic and biochemical approaches validate our network analysis and show that CLIPB4 is required for melanization and antibacterial immunity, acting as a prophenoloxidase (proPO)-activating protease, which is inhibited by SRPN2. In addition, we provide novel insight into the structural organization of the cSP network in An. gambiae, by demonstrating that CLIPB4 is able to activate proCLIPB8, a cSP upstream of the proPO-activating protease CLIPB9. These data provide the first evidence that, in mosquitoes, cSPs provide branching points in immune protease networks and deliver positive reinforcement in proPO activation cascades.
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Affiliation(s)
- Xiufeng Zhang
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Shasha Zhang
- Division of Biology, Kansas State University, Manhattan, KS, USA
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Junyao Kuang
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
| | | | - Bianca Morejon
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Sally A. Saab
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Miao Li
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Eve C. Metto
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | - Chunju An
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China
| | | | - Mike A. Osta
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Caterina Scoglio
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS, USA
| | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, KS, USA
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Zhang X, Zhang S, Kuang J, Sellens KA, Morejon B, Saab SA, Li M, Metto EC, An C, Culbertson CT, Osta MA, Scoglio C, Michel K. CLIPB4 is a central node in the protease network that regulates humoral immunity in Anopheles gambiae mosquitoes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.07.545904. [PMID: 37461554 PMCID: PMC10350057 DOI: 10.1101/2023.07.07.545904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
Insect humoral immune responses are regulated in part by protease cascades, whose components circulate as zymogens in the hemolymph. In mosquitoes, these cascades consist of clip domain serine proteases (cSPs) and/or their non-catalytic homologs (cSPHs), which form a complex network, whose molecular make-up is not fully understood. Using a systems biology approach, based on a co-expression network of gene family members that function in melanization and co-immunoprecipitation using the serine protease inhibitor (SRPN)2, a key negative regulator of the melanization response in mosquitoes, we identify the cSP CLIPB4 from the African malaria mosquito Anopheles gambiae as a central node in this protease network. CLIPB4 is tightly co-expressed with SRPN2 and forms protein complexes with SRPN2 in the hemolymph of immune-challenged female mosquitoes. Genetic and biochemical approaches validate our network analysis and show that CLIPB4 is required for melanization and antibacterial immunity, acting as a prophenoloxidase (proPO)-activating protease, which is inhibited by SRPN2. In addition, we provide novel insight into the structural organization of the cSP network in An. gambiae, by demonstrating that CLIPB4 is able to activate proCLIPB8, a cSP upstream of the proPO-activating protease CLIPB9. These data provide the first evidence that, in mosquitoes, cSPs provide branching points in immune protease networks and deliver positive reinforcement in proPO activation cascades.
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Affiliation(s)
- Xiufeng Zhang
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Shasha Zhang
- Division of Biology, Kansas State University, Manhattan, KS, USA
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Junyao Kuang
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506, USA
| | | | - Bianca Morejon
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Sally A. Saab
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Miao Li
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Eve C. Metto
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | - Chunju An
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China
| | | | - Mike A. Osta
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Caterina Scoglio
- Department of Electrical and Computer Engineering, Kansas State University, Manhattan, KS 66506, USA
| | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, KS, USA
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Dittmer NT, Hiromasa Y, Kanost MR. Proteomic analysis of pharate pupal molting fluid from the tobacco hornworm, Manduca sexta. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 149:103844. [PMID: 36115517 PMCID: PMC9875806 DOI: 10.1016/j.ibmb.2022.103844] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 08/30/2022] [Accepted: 09/09/2022] [Indexed: 06/15/2023]
Abstract
The insect cuticle is a key component of their success, being important for protection, communication, locomotion, and support. Conversely, as an exoskeleton, it also limits the size of the insect and must be periodically molted and a new one synthesized, to permit growth. To achieve this, the insect secretes a solution of chitinases, proteases and other proteins, known collectively as molting fluid, during each molting process to break down and recycle components of the old cuticle. Previous research has focused on the degradative enzymes in molting fluid and offered some characterization of their biochemical properties. However, identification of the specific proteins involved remained to be determined. We have used 2D SDS-PAGE and LC/MS-based proteomic analysis to identify proteins in the molting fluid of the tobacco hornworm, Manduca sexta, undergoing the larval to pupal molt. We categorized these proteins based on their proposed functions including chitin metabolism, proteases, peptidases, and immunity. This analysis complements previous reported work on M. sexta molting fluid and identifies candidate genes for enzymes involved in cuticle remodeling. Proteins classified as having an immune function highlight potential for molting fluid to act as an immune barrier to prevent infections during the cuticle degradation and ecdysis processes. Several proteins known to function in melanin synthesis as an immune response in hemolymph were present in molting fluid. We demonstrated that the bacterium Micrococcus luteus and the entomopathogenic fungus Beauveria bassiana can stimulate activation of phenoloxidase in molting fluid, indicating that the recognition proteins, protease cascade, and prophenoloxidase needed for melanin synthesis are present as a defense against infection during cuticle degradation. This analysis offers insights for proteins that may be important not only for molting in M. sexta but for insects in general.
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Affiliation(s)
- Neal T Dittmer
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA.
| | - Yasuaki Hiromasa
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA
| | - Michael R Kanost
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA
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Rios-Díez JD, Meriño-Cabrera Y, Silva-Junior NR, de Almeida Barros R, Aguilar de Oliveira J, Josué de Oliveira Ramos H, Goreti de Almeida Oliveira M. Novel proteinase inhibitor from the hemolymph of soybean pest Anticarsia gemmatalis (lepidóptera: Noctuidae): Structural modeling and enzymatic kinetic. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2022; 109:e21864. [PMID: 34982841 DOI: 10.1002/arch.21864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/12/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
New approaches are needed to reduce risks to the environment and natural enemies and to avoid or delay the onset of insecticide resistance. The use of insecticides based on proteinase inhibitors of hemolymph is an alternative for the control of Lepidoptera pests primarily by having low toxicity and short persistence in the environment. Thus, in this study, we describe the purification process and identification of protease inhibitors from hemolymph Anticarsia gemmatalis and their activities against trypsin enzymes. Furthermore, the three-dimensional (3D) structure of the inhibitor and binding mode to trypsin enzymes was determined, and the stability of the inhibitory activity in several pHs and temperature values was evaluated. The inhibitor was characterized as a serpin family inhibitor and named A. gemmatalis hemolymph serpin inhibitor (AHSI), with an approximate mass of 38 ± 2 kDa, highly stable to temperature and pH variations, and with inhibitory capacity on bovine trypsin and gut trypsin of A. gemmatalis demonstrated by calculated Ki values and affinity energy through molecular docking, being a reversible competitive inhibitor that binds to the active site of trypsin-like enzymes. We conclude that the AHSI inhibitor identified from the hemolymph of the soybean pest A. gemmatalis preserves the original structure of the serpin family with a good overall stereochemical quality confirmed from molecular modeling. The docking analysis showed that the reactive site of the inhibitor is in contact with the catalytic cavity of the trypsin with high-affinity energy.
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Affiliation(s)
- Juan D Rios-Díez
- Deparment of Entomology, BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Yaremis Meriño-Cabrera
- Department of Biochemistry and Molecular Biology, BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | | | - Rafael de Almeida Barros
- Department of Biochemistry and Molecular Biology, BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - João Aguilar de Oliveira
- Department of Biochemistry and Molecular Biology, BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Humberto Josué de Oliveira Ramos
- Department of Biochemistry and Molecular Biology, BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
- Center of Analysis of Biomolecules, NuBioMol, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
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Gu Q, Wu Z, Zhou Y, Wang Z, Huang J, Shi M, Chen X. A serpin (CvT-serpin15) of teratocytes contributes to microbial-resistance in Plutella xylostella during Cotesia vestalis parasitism. PEST MANAGEMENT SCIENCE 2021; 77:4730-4740. [PMID: 34155805 PMCID: PMC9292400 DOI: 10.1002/ps.6515] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/25/2021] [Accepted: 06/21/2021] [Indexed: 05/02/2023]
Abstract
BACKGROUND Parasitic wasps are an important group of entomophagous insects for pest control. As parasitic wasps often lay eggs on or into their associated hosts, parasitoids evolve to utilize several factors including venom, polydnavirus (PDV) to alter host physiology for successful parasitism. Some taxa of endoparasitoids produce teratocytes, which are a type of cell that is released into host insects when wasp eggs hatch. Teratocytes display multifunction in parasitism such as host nutritional exploration, immune and developmental regulation, by secreting plenty of proteins into host hemocoel. RESULTS A serpin (CvT-serpin15) secreted by teratocytes was characterized. QPCR results showed the expressional level of CvT-serpin15 was upregulated following bacterial challenges. Enzyme activity experiment indicated the recombinant CvT-serpin15 protein could interfere with the growth of Gram-positive bacteria Staphylococcus aureus. The survival rate assay demonstrated CvT-serpin15 increased survival rate of Plutella xylostella infected by S. aureus. CONCLUSION CvT-serpin15 secreted by teratocytes would boost the host immune system when pathogens invade host hemocoel during parasitism, and ultimately protect the development of wasp larva from bacterial infection. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Qijuan Gu
- Institute of Insect SciencesZhejiang UniversityHangzhouChina
- College of Agriculture and Food ScienceZhejiang Agriculture & Forestry UniversityHangzhouChina
| | - Zhiwei Wu
- Institute of Insect SciencesZhejiang UniversityHangzhouChina
| | - Yuenan Zhou
- Institute of Insect SciencesZhejiang UniversityHangzhouChina
| | - Zhizhi Wang
- Institute of Insect SciencesZhejiang UniversityHangzhouChina
| | - Jianhua Huang
- Institute of Insect SciencesZhejiang UniversityHangzhouChina
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang ProvinceZhejiang UniversityHangzhouChina
| | - Min Shi
- Institute of Insect SciencesZhejiang UniversityHangzhouChina
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect PestsZhejiang UniversityHangzhouChina
| | - Xuexin Chen
- Institute of Insect SciencesZhejiang UniversityHangzhouChina
- State Key Lab of Rice BiologyZhejiang UniversityHangzhouChina
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Zhang X, Li M, El Moussawi L, Saab S, Zhang S, Osta MA, Michel K. CLIPB10 is a Terminal Protease in the Regulatory Network That Controls Melanization in the African Malaria Mosquito Anopheles gambiae. Front Cell Infect Microbiol 2021; 10:585986. [PMID: 33520733 PMCID: PMC7843523 DOI: 10.3389/fcimb.2020.585986] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/30/2020] [Indexed: 12/19/2022] Open
Abstract
Humoral immune responses in animals are often tightly controlled by regulated proteolysis. This proteolysis is exerted by extracellular protease cascades, whose activation culminates in the proteolytic cleavage of key immune proteins and enzymes. A model for such immune system regulation is the melanization reaction in insects, where the activation of prophenoxidase (proPO) leads to the rapid formation of eumelanin on the surface of foreign entities such as parasites, bacteria and fungi. ProPO activation is tightly regulated by a network of so-called clip domain serine proteases, their proteolytically inactive homologs, and their serpin inhibitors. In Anopheles gambiae, the major malaria vector in sub-Saharan Africa, manipulation of this protease network affects resistance to a wide range of microorganisms, as well as host survival. However, thus far, our understanding of the molecular make-up and regulation of the protease network in mosquitoes is limited. Here, we report the function of the clip domain serine protease CLIPB10 in this network, using a combination of genetic and biochemical assays. CLIPB10 knockdown partially reversed melanotic tumor formation induced by Serpin 2 silencing in the absence of infection. CLIPB10 was also partially required for the melanization of ookinete stages of the rodent malaria parasite Plasmodium berghei in a refractory mosquito genetic background. Recombinant serpin 2 protein, a key inhibitor of the proPO activation cascade in An. gambiae, formed a SDS-stable protein complex with activated recombinant CLIPB10, and efficiently inhibited CLIPB10 activity in vitro at a stoichiometry of 1.89:1. Recombinant activated CLIPB10 increased PO activity in Manduca sexta hemolymph ex vivo, and directly activated purified M. sexta proPO in vitro. Taken together, these data identify CLIPB10 as the second protease with prophenoloxidase-activating function in An. gambiae, in addition to the previously described CLIPB9, suggesting functional redundancy in the protease network that controls melanization. In addition, our data suggest that tissue melanization and humoral melanization of parasites are at least partially mediated by the same proteases.
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Affiliation(s)
- Xin Zhang
- Division of Biology, Kansas State University, Manhattan, KS, United States
| | - Miao Li
- Division of Biology, Kansas State University, Manhattan, KS, United States
| | - Layla El Moussawi
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Sally Saab
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Shasha Zhang
- Division of Biology, Kansas State University, Manhattan, KS, United States.,Department of Entomology, China Agricultural University, Beijing, China
| | - Mike A Osta
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, KS, United States
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9
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Li M, Takahashi D, Kanost MR. Peptides based on the reactive center loop of Manduca sexta serpin-3 block its protease inhibitory function. Sci Rep 2020; 10:11497. [PMID: 32661389 PMCID: PMC7359039 DOI: 10.1038/s41598-020-68316-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 06/23/2020] [Indexed: 11/11/2022] Open
Abstract
One innate immune response in insects is the proteolytic activation of hemolymph prophenoloxidase (proPO), regulated by protease inhibitors called serpins. In the inhibition reaction of serpins, a protease cleaves a peptide bond in a solvent-exposed reactive center loop (RCL) of the serpin, and the serpin undergoes a conformational change, incorporating the amino-terminal segment of the RCL into serpin β-sheet A as a new strand. This results in an irreversible inhibitory complex of the serpin with the protease. We synthesized four peptides with sequences from the hinge region in the RCL of Manduca sexta serpin-3 and found they were able to block serpin-3 inhibitory activity, resulting in suppression of inhibitory protease-serpin complex formation. An RCL-derived peptide with the sequence Ser-Val-Ala-Phe-Ser (SVAFS) displayed robust blocking activity against serpin-3. Addition of acetyl-SVAFS-amide to hemolymph led to unregulated proPO activation. Serpin-3 associated with Ac-SVAFS-COO− had an altered circular dichroism spectrum and enhanced thermal resistance to change in secondary structure, indicating that these two molecules formed a binary complex, most likely by insertion of the peptide into β-sheet A. The interference of RCL-derived peptides with serpin activity may lead to new possibilities of “silencing” arthropod serpins with unknown functions for investigation of their physiological roles.
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Affiliation(s)
- Miao Li
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA
| | - Daisuke Takahashi
- Department of Pharmaceutical Health Care and Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Michael R Kanost
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA.
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10
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Nosema bombycis suppresses host hemolymph melanization through secreted serpin 6 inhibiting the prophenoloxidase activation cascade. J Invertebr Pathol 2019; 168:107260. [DOI: 10.1016/j.jip.2019.107260] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 10/09/2019] [Accepted: 10/12/2019] [Indexed: 01/09/2023]
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11
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A systemic study of indoxacarb resistance in Spodoptera litura revealed complex expression profiles and regulatory mechanism. Sci Rep 2019; 9:14997. [PMID: 31628365 PMCID: PMC6802196 DOI: 10.1038/s41598-019-51234-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 09/24/2019] [Indexed: 11/09/2022] Open
Abstract
The tobacco cutworm, Spodoptera litura, is an important pest of crop and vegetable plants worldwide, and its resistance to insecticides have quickly developed. However, the resistance mechanisms of this pest are still unclear. In this study, the change in mRNA and miRNA profiles in the susceptible, indoxacarb-resistant and field indoxacarb-resistant strains of S. litura were characterized. Nine hundred and ten co-up-regulated and 737 co-down-regulated genes were identified in the resistant strains. Further analysis showed that 126 co-differentially expressed genes (co-DEGs) (cytochrome P450, carboxy/cholinesterase, glutathione S-transferase, ATP-binding cassette transporter, UDP-glucuronosyl transferase, aminopeptidase N, sialin, serine protease and cuticle protein) may play important roles in indoxacarb resistance in S. litura. In addition, a total of 91 known and 52 novel miRNAs were identified, and 10 miRNAs were co-differentially expressed in the resistant strains of S. litura. Furthermore, 10 co-differentially expressed miRNAs (co-DEmiRNAs) had predicted co-DEGs according to the expected miRNA-mRNA negative regulation pattern and 37 indoxacarb resistance-related co-DEGs were predicted to be the target genes. These results not only broadened our understanding of molecular mechanisms of insecticide resistance by revealing complicated profiles, but also provide important clues for further study on the mechanisms of miRNAs involved in indoxacarb resistance in S. litura.
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12
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Lü D, Xu P, Hou C, Gao K, Guo X. Label-free LC-MS/MS proteomic analysis of the hemolymph of silkworm larvae infected with Beauveria bassiana. J Invertebr Pathol 2019; 166:107227. [PMID: 31386830 DOI: 10.1016/j.jip.2019.107227] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 11/16/2022]
Abstract
Beauveria bassiana, a pathogen of the economically important silkworm (Bombyx mori), causes serious losses in the sericulture industry; however, the mechanisms underlying B. bassiana infection and the silkworm response are not fully understood. To obtain new insights into the interaction between B. bassiana and its host, hemolymph samples from fifth instar silkworm larvae infected with B. bassiana were analyzed at 36-h post-inoculation using a label-free LC-MS/MS proteomic technique. In total, 671 proteins were identified in the hemolymph, including 87 differentially expressed proteins, 42 up-regulated and 45 down-regulated in infected larvae. Six were detected only in infected larvae, and five were detected only in uninfected larvae. Based on GO annotations, 48 of the differentially expressed proteins were involved in molecular functions, 42 were involved in biological processes, and 39 were involved in cell components. A KEGG pathway analysis indicated that these differentially expressed proteins participate in 85 signal transduction pathways, including the amoebiasis, MAPK signaling, Hippo signaling, Toll and Imd signaling, and lysosome pathways. The silkworm hemolymph is the main site for B. bassiana replication. We identified differentially expressed proteins involved in the regulation of the host response to B. bassiana infection, providing important experimental data for the identification of key factors contributing to the interaction between the pathogenic fungus and its host.
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Affiliation(s)
| | - Ping Xu
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Chengxiang Hou
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Kun Gao
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Xijie Guo
- Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang 212018, China.
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13
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Wang L, Liu H, Fu H, Zhang L, Guo P, Xia Q, Zhao P. Silkworm serpin32 functions as a negative-regulator in prophenoloxidase activation. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2019; 91:123-131. [PMID: 30339875 DOI: 10.1016/j.dci.2018.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 10/15/2018] [Accepted: 10/15/2018] [Indexed: 06/08/2023]
Abstract
The extracellular serine protease cascade is an essential component of insect humoral immunity. Serine protease inhibitors (serpins) play an important regulatory role in the process of insect immunity by regulating the serine protease cascade pathway. We aimed to clarify the function of Bmserpin32 in this study. First, we performed homologous sequence alignment and phylogenetic analysis of Bmserpin32. Bmserpin32 was found to share 64% amino acid sequence identity with Manduca sexta serpin7, an immunomodulatory protein. Bmserpin32 cDNA was cloned, and the recombinant Bmserpin32 protein was expressed in Escherichia coli and purified by nickel-nitrilotriacetic acid affinity and gel filtration chromatography. The activity assay showed that Bmserpin32 had significant inhibitory activity against trypsin. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry and site-directed mutagenesis combined with activity assays indicated that the cleavage site of Bmserpin32 is between Arg359 and Ile360. After infection with E. coli or Micrococcus luteus, the expression level of Bmserpin32 in immune-related tissues was significantly upregulated. In addition, Bmserpin32 could delay or inhibit the melanization of hemolymph by inhibiting the activation of prophenoloxidase in larval hemolymph. Furthermore, a physiological target of Bmserpin32 was identified as the clip protease, BmPAP3, an apparent ortholog of M. sexta propenoloxidase-activating protease-3. Our observations enable a better understanding of the physiological role of Bmserpin32 in regulating melanization in silkworm.
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Affiliation(s)
- Luoling Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Huawei Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Huanyi Fu
- College of Biotechnology, Southwest University, Chongqing, China
| | - Lu Zhang
- College of Biotechnology, Southwest University, Chongqing, China
| | - Pengchao Guo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.
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14
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Wang X, Luo H, Zhang R. Innate immune responses in the Chinese oak silkworm, Antheraea pernyi. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 83:22-33. [PMID: 29241953 DOI: 10.1016/j.dci.2017.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/10/2017] [Accepted: 12/11/2017] [Indexed: 06/07/2023]
Abstract
Innate immunity, the evolutionarily conserved defense system, has been extensively analyzed in insect models over recent decades. The significant progress in this area has formed our dominant conceptual framework of the innate immune system, but critical advances in other insects have had a profound impact on our insights into the mystery of innate immunity. In recent years, we focused on the immune responses in Antheraea pernyi, an important commercial silkworm species reared in China. Here, we review the immune responses of A. pernyi based on immune-related gene-encoded proteins that are divided into five categories, namely pattern recognition receptors, hemolymph proteinases and their inhibitors, prophenoloxidase, Toll pathway factors and antimicrobial peptides, and others. Although the summarized information is limited since the research on A. pernyi immunity is in its infancy, we hope to provide evidence for further exploration of innate immune mechanisms.
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Affiliation(s)
- Xialu Wang
- School of Medical Devices, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China
| | - Hao Luo
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China
| | - Rong Zhang
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China.
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15
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Gene expression profiling provides insights into the immune mechanism of Plutella xylostella midgut to microbial infection. Gene 2018; 647:21-30. [DOI: 10.1016/j.gene.2018.01.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 12/29/2017] [Accepted: 01/02/2018] [Indexed: 12/14/2022]
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16
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Kausar S, Abbas MN, Qian C, Zhu B, Gao J, Sun Y, Wang L, Wei G, Liu C. Role of Antheraea pernyi serpin 12 in prophenoloxidase activation and immune responses. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2018; 97:e21435. [PMID: 29193264 DOI: 10.1002/arch.21435] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Serine protease inhibitors play a key role in the immune system of invertebrates by controlling proteolytic cascades. Besides its importance, the knowledge on immune functions of serpins in most of insects is fragmentary. In the present study, we identified serpin-12 from Antheraea pernyi encoding a predicted 402 amino acid residue protein (Apserpin-12). We expressed the recombinant protein in Escherichia coli and the purified protein was used for the synthesis of rabbit anti-Apserpin-12 polyclonal antibodies and functional studies. Quantitative real-time ploymerase chain reaction (qRT-PCR) analysis revealed that the knock-down of Apserpin-12 enhanced the prophenoloxidase (PPO) cascade stimulated by Micrococcus luteus in hemolymph, whereas addition of recombinant Apserpin-12 protein along with same elicitor led to down-regulate PPO activation. Following different microbial challenge (E. coli, Beauveria bassiana, M. Luteus, and nuclear polyhedrosis virus), the expression of Apserpin-12 mRNA was induced significantly. Furthermore, the Apserpin-12 double-stranded RNA administration elicited the expression of antimicrobial peptides, while the treatment with recombinant protein suppressed their expression. Tissue profile of Apserpin-12 indicated that it is expressed in all examined tissues, that is, hemolymph, malpighian tubules, midgut, silk gland, integument, and fat body with variation in their transcript levels. We concluded that Apserpin-12 may regulate PPO activation and inhibit the production of antimicrobial peptides in A. pernyi, suggesting important role in its immune system.
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Affiliation(s)
- Saima Kausar
- College of Life Sciences, Anhui Agricultural University, Hefei, China
| | | | - Cen Qian
- College of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Baojian Zhu
- College of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Jin Gao
- College of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Yu Sun
- College of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Lei Wang
- College of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Guoqing Wei
- College of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Chaoliang Liu
- College of Life Sciences, Anhui Agricultural University, Hefei, China
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17
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He Y, Wang Y, Zhao P, Rayaprolu S, Wang X, Cao X, Jiang H. Serpin-9 and -13 regulate hemolymph proteases during immune responses of Manduca sexta. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 90:71-81. [PMID: 28987647 PMCID: PMC5673523 DOI: 10.1016/j.ibmb.2017.09.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 09/24/2017] [Accepted: 09/30/2017] [Indexed: 06/01/2023]
Abstract
Serpins are a superfamily of proteins, most of which inhibit cognate serine proteases by forming inactive acyl-enzyme complexes. In the tobacco hornworm Manduca sexta, serpin-1, -3 through -7 negatively regulate a hemolymph serine protease system that activates precursors of the serine protease homologs (SPHs), phenoloxidases (POs), Spätzles, and other cytokines. Here we report the cloning and characterization of M. sexta serpin-9 and -13. Serpin-9, a 402-residue protein most similar to Drosophila Spn77Ba, has R366 at the P1 position right before the cleavage site; Serpin-13, a 444-residue ortholog of Drosophila Spn28Dc, is longer than the other seven serpins and has R410 as the P1 residue. Both serpins are mainly produced in fat body and secreted into plasma to function. While their mRNA and protein levels were not up-regulated upon immune challenge, they blocked protease activities and affected proPO activation in hemolymph. Serpin-9 inhibited human neutrophil elastase, cathepsin G, trypsin, and chymotrypsin to different extents; serpin-13 reduced trypsin activity to approximately 10% at a molar ratio of 4:1 (serpin: enzyme). Serpin-9 was cleaved at Arg366 by the enzymes with different specificity, but serpin-13 had four P1 sites (Arg410 for trypsin-like proteases, Gly406 and Ala409 for the elastase and Thr404 for cathepsin G). Supplementation of induced cell-free hemolymph (IP, P for plasma) with recombinant serpin-9 did not noticeably affect proPO activation, but slightly reduced the PO activity increase after 0-50% ammonium sulfate fraction of the IP had been elicited by bacteria. In comparison, addition of recombinant serpin-13 significantly inhibited proPO activation in IP and the suppression was stronger in the fraction of IP. Serpin-9- and -13-containing protein complexes were isolated from IP using their antibodies. Hemolymph protease-1 precursor (proHP1), HP6 and HP8 were found to be associated with serpin-9, whereas proHP1, HP2 and HP6 were pulled downed with serpin-13. These results indicate that both serpins regulate immune proteases in hemolymph of M. sexta larvae.
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Affiliation(s)
- Yan He
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Yang Wang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Picheng Zhao
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Subrahmanyam Rayaprolu
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Xiuhong Wang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Xiaolong Cao
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA.
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18
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Kausar S, Abbas MN, Qian C, Zhu B, Sun Y, Sun Y, Wang L, Wei G, Maqsood I, Liu CL. Serpin-14 negatively regulates prophenoloxidase activation and expression of antimicrobial peptides in Chinese oak silkworm Antheraea pernyi. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 76:45-55. [PMID: 28545959 DOI: 10.1016/j.dci.2017.05.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 05/21/2017] [Accepted: 05/21/2017] [Indexed: 06/07/2023]
Abstract
Genes encoding proteins of serpins superfamily are widely distributed in invertebrates. In insects, serpins play important roles in regulating immune responses and other physiological processes. Here, we report the cloning and characterization of cDNA of Apserpin-14 from Chinese oak silkworm (Antheraea pernyi). The Apserpin-14 gene contains 1206 bp open reading frame, encoding a predicted 401 amino acid residue protein. We expressed the recombinant Apserpin-14 protein in Escherichia coli and then purified protein was used to prepare rabbit anti-Apserpin-14 polyclonal antibodies. Quantitative real-time PCR analysis revealed that mRNA level of Apserpin-14 was highest in the fat body, whereas, among developmental stages the 5th instar and pupal stage showed greatest expression. Furthermore, Escherichia coli, Beauveria bassiana, Micrococcus luteus and nuclear polyhedrosis virus challenge enhanced Apserpin-14 transcript in both the fat body and hemocyte. Recombinant Apserpin-14 added to hemolymph inhibited spontaneous melanization and suppressed prophenoloxidase activation stimulated by M. luteus, but did not affect phenoloxidase (PO) activity. Injection of recombinant Apserpin-14 protein into A. pernyi larvae significantly reduced the transcript levels of antimicrobial peptides in the fat body, while its depletion by double stranded RNA enhanced their expression. We concluded that Apserpin-14 likely involved in regulation of proPO activation and production of antimicrobial peptides, implying its important role in the innate immune system of A. pernyi.
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Affiliation(s)
- Saima Kausar
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
| | | | - Cen Qian
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
| | - Baojian Zhu
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
| | - Yu Sun
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
| | - Yuxuan Sun
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
| | - Lei Wang
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
| | - Guoqing Wei
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
| | - Iram Maqsood
- College of Wildlife Resources, Department of Wildlife Conservation and Utilization, Northeast Forestry University Harbin, China.
| | - Chao-Liang Liu
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
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19
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He Y, Wang Y, Yang F, Jiang H. Manduca sexta hemolymph protease-1, activated by an unconventional non-proteolytic mechanism, mediates immune responses. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 84:23-31. [PMID: 28366787 PMCID: PMC5461656 DOI: 10.1016/j.ibmb.2017.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 03/06/2017] [Accepted: 03/28/2017] [Indexed: 05/27/2023]
Abstract
Tissue damage or pathogen invasion triggers the auto-proteolysis of an initiating serine protease (SP), rapidly leading to sequential cleavage activation of other cascade members to set off innate immune responses in insects. Recently, we presented evidence that Manduca sexta hemolymph protease-1 zymogen (proHP1) is a member of the SP system in this species, and may activate proHP6. HP6 stimulates melanization and induces antimicrobial peptide synthesis. Here we report that proHP1 adopts an active conformation (*) to carry out its function, without a requirement for proteolytic activation. Affinity chromatography using HP1 antibodies isolated from induced hemolymph the 48 kDa proHP1 and also a 90 kDa band (detected by SDS-PAGE under reducing conditions) containing proHP1 and several serpins, as revealed by mass spectrometric analysis. Identification of tryptic peptides from these 90 kDa complexes included peptides from the amino-terminal regulatory part of proHP1, indicating that proHP1* was not cleaved, and that it had formed a complex with the serpins. As suicide inhibitors, serpins form SDS-stable, acyl-complexes when they are attacked by active proteases, indicating that proHP1* was catalytically active. Detection of M. sexta serpin-1, 4, 9, 13 and smaller amounts of serpin-3, 5, 6 in the complexes suggests that it is regulated by multiple serpins in hemolymph. We produced site-directed mutants of proHP1b for cleavage by bovine blood coagulation factor Xa at the designed proteolytic activation site, to generate a form of proHP1b that could be activated by Factor Xa. However, proHP1b cut by Factor Xa failed to activate proHP6 and, via HP6, proHP8 or proPAP1. This negative result is consistent with the suggestion that proHP1* is a physiological mediator of immune responses. Further research is needed to investigate the conformational change that results in conversion of proHP1 to active proHP1*.
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Affiliation(s)
- Yan He
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Yang Wang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Fan Yang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA.
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20
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Sutthangkul J, Amparyup P, Eum JH, Strand MR, Tassanakajon A. Anti-melanization mechanism of the white spot syndrome viral protein, WSSV453, via interaction with shrimp proPO-activating enzyme, PmproPPAE2. J Gen Virol 2017; 98:769-778. [DOI: 10.1099/jgv.0.000729] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Jantiwan Sutthangkul
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
| | - Piti Amparyup
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong1, Klong Luang, Pathumthani 12120, Thailand
| | - Jai-Hoon Eum
- Department of Entomology, University of Georgia, Athens, GA 30602, USA
| | - Michael R Strand
- Department of Entomology, University of Georgia, Athens, GA 30602, USA
| | - Anchalee Tassanakajon
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
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21
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Wang X, Wang K, He Y, Lu X, Wen D, Wu C, Zhang J, Zhang R. The functions of serpin-3, a negative-regulator involved in prophenoloxidase activation and antimicrobial peptides expression of Chinese oak silkworm, Antheraea pernyi. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 69:1-11. [PMID: 27919647 DOI: 10.1016/j.dci.2016.11.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 06/06/2023]
Abstract
Serpins are a superfamily of proteins engaged in various physiological processes in all kingdoms of life. To date, many striking results have demonstrated serpins are involved in the invertebrate immune system by regulating the proteolytic cascades. However, in most insect species, the immune functions of serpins in response against pathogen invasion remain obscure. In this study, we identified a full-length cDNA sequence of serpin, named serpin-3, from the Chinese oak silkworm Antheraea pernyi. Sequence alignments have indicated that Apserpin-3 might regulate the melanization reaction via inhibiting prophenoloxidases-activating protease(s) in plasma. Furthermore, it was detected to be primarily transcribed within the fat body, epidermis and hemocytes with significant induction following immune-challenge. Further studies have shown that the knockdown of serpin-3 up-regulated the prophenoloxidases cascade stimulated by pathogen in hemolymph, while the addition of recombinant serpin-3 along with the same elicitor led to the suppressed activation of prophenoloxidase. Besides, the injection of dsRNA of serpin-3 caused the elevated expression of antimicrobial peptides. Altogether, we arrived at a conclusion that serpin-3 might act as a negative-regulator in prophenoloxidases activation and inhibit the production of antimicrobial peptides in Antheraea pernyi larvae.
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Affiliation(s)
- Xialu Wang
- School of Medical Devices, Shenyang Pharmaceutical University, China
| | - Kailin Wang
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China
| | - Yuanyuan He
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China
| | - Xinrui Lu
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China
| | - Daihua Wen
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China
| | - Chunfu Wu
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China
| | - Jinghai Zhang
- School of Medical Devices, Shenyang Pharmaceutical University, China
| | - Rong Zhang
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China.
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22
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Ponprateep S, Vatanavicharn T, Lo CF, Tassanakajon A, Rimphanitchayakit V. Alpha-2-macroglobulin is a modulator of prophenoloxidase system in pacific white shrimp Litopenaeus vannamai. FISH & SHELLFISH IMMUNOLOGY 2017; 62:68-74. [PMID: 28027986 DOI: 10.1016/j.fsi.2016.12.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 12/16/2016] [Accepted: 12/22/2016] [Indexed: 06/06/2023]
Abstract
The shrimp multifunctional protein alpha-2-macroglobulin (A2M) is abundantly expressed in plasma, highly up-regulated upon microbial infection and involved in several immune pathways such as blood clotting system, phagocytosis and melanization. Herein, the function of LvA2M from Litopenaeus vannamei on the prophenoloxidase (proPO) system is reported. The recombinant (r)LvA2M produced strongly and specifically inhibited trypsin and the PO activity in shrimp plasma in a dose-dependent manner. Silencing of LvA2M led to an increase in the PO activity in shrimp plasma although the expression of proPO-associated genes, proPO-activating enzyme (PPAE) and prophenoloxidase (proPO) but not the proPO-activating factor (PPAF) was down-regulated. In Vibrio parahaemolyticus AHPND-infected shrimp, the LvA2M activity was suppressed in an early phase of infection while the PO activity was increased. Thus, the proPO-activating system was regulated by the LvA2M.
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Affiliation(s)
- Sirikwan Ponprateep
- Department of Chemistry, Faculty of Science, Srinakharinwirot University, 114 Sukhumvit 23 Road, Bangkok 10110, Thailand.
| | - Tipachai Vatanavicharn
- Applied Analytical Chemistry Research Unit, Department of Chemistry, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Chalongkrung Road, Bangkok 10520, Thailand
| | - Chu Fang Lo
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Anchalee Tassanakajon
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand
| | - Vichien Rimphanitchayakit
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand.
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23
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Serpins in arthropod biology. Semin Cell Dev Biol 2016; 62:105-119. [PMID: 27603121 DOI: 10.1016/j.semcdb.2016.09.001] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 12/21/2022]
Abstract
Serpins are the largest known family of serine proteinase inhibitors and perform a variety of physiological functions in arthropods. Herein, we review the field of serpins in arthropod biology, providing an overview of current knowledge and topics of interest. Serpins regulate insect innate immunity via inhibition of serine proteinase cascades that initiate immune responses such as melanization and antimicrobial peptide production. In addition, several serpins with anti-pathogen activity are expressed as acute-phase serpins in insects upon infection. Parasitoid wasps can downregulate host serpin expression to modulate the host immune system. In addition, examples of serpin activity in development and reproduction in Drosophila have also been discovered. Serpins also function in host-pathogen interactions beyond immunity as constituents of venom in parasitoid wasps and saliva of blood-feeding ticks and mosquitoes. These serpins have distinct effects on immunosuppression and anticoagulation and are of interest for vaccine development. Lastly, the known structures of arthropod serpins are discussed, which represent the serpin inhibitory mechanism and provide a detailed overview of the process.
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He Y, Cao X, Zhang S, Rogers J, Hartson S, Jiang H. Changes in the Plasma Proteome of Manduca sexta Larvae in Relation to the Transcriptome Variations after an Immune Challenge: Evidence for High Molecular Weight Immune Complex Formation. Mol Cell Proteomics 2016; 15:1176-87. [PMID: 26811355 DOI: 10.1074/mcp.m115.054296] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Indexed: 11/06/2022] Open
Abstract
Manduca sextais a lepidopteran model widely used to study insect physiological processes, including innate immunity. In this study, we explored the proteomes of cell-free hemolymph from larvae injected with a sterile buffer (C for control) or a mixture of bacteria (I for induced). Of the 654 proteins identified, 70 showed 1.67 to >200-fold abundance increases after the immune challenge; 51 decreased to 0-60% of the control levels. While there was no strong parallel between plasma protein levels and their transcript levels in hemocytes or fat body, the mRNA level changes (i.e.I/C ratios of normalized read numbers) in the tissues concurred with their protein level changes (i.e.I/C ratios of normalized spectral counts) with correlation coefficients of 0.44 and 0.57, respectively. Better correlations support that fat body contributes a more significant portion of the plasma proteins involved in various aspects of innate immunity. Consistently, ratios of mRNA and protein levels were better correlated for immunity-related proteins than unrelated ones. There is a set of proteins whose apparent molecular masses differ considerably from the calculatedMr's, suggestive of posttranslational modifications. In addition, some lowMrproteins were detected in the range of 80 to >300 kDa on a reducing SDS-polyacrylamide gel, indicating the existence of highMrcovalent complexes. We identified 30 serine proteases and their homologs, 11 of which are known members of an extracellular immune signaling network. Along with our quantitative transcriptome data, the protein identification, inducibility, and association provide leads toward a focused exploration of humoral immunity inM. sexta.
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Affiliation(s)
- Yan He
- From the ‡Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078
| | - Xiaolong Cao
- From the ‡Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078; §Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078
| | - Shuguang Zhang
- From the ‡Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078
| | - Janet Rogers
- §Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078
| | - Steve Hartson
- §Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078
| | - Haobo Jiang
- From the ‡Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078;
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Adamo SA, Davies G, Easy R, Kovalko I, Turnbull KF. Reconfiguration of the immune system network during food limitation in the caterpillar Manduca sexta. ACTA ACUST UNITED AC 2016; 219:706-18. [PMID: 26747906 DOI: 10.1242/jeb.132936] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/17/2015] [Indexed: 11/20/2022]
Abstract
Dwindling resources might be expected to induce a gradual decline in immune function. However, food limitation has complex and seemingly paradoxical effects on the immune system. Examining these changes from an immune system network perspective may help illuminate the purpose of these fluctuations. We found that food limitation lowered long-term (i.e. lipid) and short-term (i.e. sugars) energy stores in the caterpillar Manduca sexta. Food limitation also: altered immune gene expression, changed the activity of key immune enzymes, depressed the concentration of a major antioxidant (glutathione), reduced resistance to oxidative stress, reduced resistance to bacteria (Gram-positive and -negative bacteria) but appeared to have less effect on resistance to a fungus. These results provide evidence that food limitation led to a restructuring of the immune system network. In severely food-limited caterpillars, some immune functions were enhanced. As resources dwindled within the caterpillar, the immune response shifted its emphasis away from inducible immune defenses (i.e. those responses that are activated during an immune challenge) and increased emphasis on constitutive defenses (i.e. immune components that are produced consistently). We also found changes suggesting that the activation threshold for some immune responses (e.g. phenoloxidase) was lowered. Changes in the configuration of the immune system network will lead to different immunological strengths and vulnerabilities for the organism.
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Affiliation(s)
- Shelley A Adamo
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Gillian Davies
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Russell Easy
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Ilya Kovalko
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Kurtis F Turnbull
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
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Liu Y, Liu T, Hou F, Wang X, Liu X. Lvserpin3 is involved in shrimp innate immunity via the inhibition of bacterial proteases and proteases involved in prophenoloxidase system. FISH & SHELLFISH IMMUNOLOGY 2016; 48:128-135. [PMID: 26432049 DOI: 10.1016/j.fsi.2015.09.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 09/16/2015] [Accepted: 09/25/2015] [Indexed: 06/05/2023]
Abstract
Serine protease inhibitor, represented by serpin, plays an important inhibitory role on proteases involved in the immune responses. To clarify the immune characterizations of serpin, a novel serpin (Lvserpin3) encoding for 410 amino acids with a 23-amino acid signal peptide and a serpin domain was identified from the Pacific white shrimp Litopenaeus vannamei. Lvserpin3 expressed strongest in hepatopancreas, and was significantly up-regulated in the early stage upon Vibrio anguillarum, Micrococcus lysodeikticus or White Spot Syndrome Virus (WSSV) infection. Suppression of Lvserpin3 by dsRNA led to a significant increase in the transcripts of LvPPAF, LvproPO and phenoloxidase (PO) activity, and also led to the high cumulative mortality. The recombinant Lvserpin3 protein (rLvserpin3) inhibited the proteases secreted by M. lysodeikticus and Bacillus subtilis, and further exhibited inhibitory role on the growth of B. subtilis and M. lysodeikticu. Moreover, rLvserpin3 was found to be able to block the activation of prophenoloxidase system. Taken together, the results imply that Lvserpin3 may be involved in shrimp innate immunity via the inhibition of bacterial proteases and proteases involved in prophenoloxidase system.
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Affiliation(s)
- Yongjie Liu
- College of Animal Science and Technology, Northwest A&F University, Shaanxi, Yangling, 712100, China
| | - Tao Liu
- College of Animal Science and Technology, Northwest A&F University, Shaanxi, Yangling, 712100, China
| | - Fujun Hou
- College of Animal Science and Technology, Northwest A&F University, Shaanxi, Yangling, 712100, China
| | - Xianzong Wang
- College of Animal Science and Technology, Northwest A&F University, Shaanxi, Yangling, 712100, China
| | - Xiaolin Liu
- College of Animal Science and Technology, Northwest A&F University, Shaanxi, Yangling, 712100, China.
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Liu Y, Cui Z, Shi G, Luo D, Wang S, Wang C. PtPLC, a pacifastin-related inhibitor involved in antibacterial defense and prophenoloxidase cascade of the swimming crab Portunus trituberculatus. FISH & SHELLFISH IMMUNOLOGY 2015; 43:36-42. [PMID: 25542376 DOI: 10.1016/j.fsi.2014.12.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 12/05/2014] [Accepted: 12/15/2014] [Indexed: 06/04/2023]
Abstract
Pacifastin-related inhibitor is a new family of serine protease inhibitors that regulate the proteolytic cascade in multiple biological processes. Contrary to the knowledge on the structure and inhibitory mechanism of pacifastin-like members in locust, very little is known about their functions. Here, we report the inhibitory activities in relation to the structural characteristics of pacifastin light chain (PtPLC) gene identified from the swimming crab Portunus trituberculatus. The mature PtPLC and five PLD-related domains with critical residues were expressed in Escherichia coli, and assayed for their activities. The recombinant PtPLC (rPtPLC) displayed inhibitory activities against trypsin and chymotrypsin in a dose dependent manner, with a preference for trypsin. Except for rPtPLC-D4, the other four rPtPLC-related domains could inhibit at least one of serine proteases. The enzyme specificity of PtPLC domains generally corresponded to the nature of the P1 residue at the reactive site. rPtPLC was able to inhibit the growth of Gram-negative bacteria Vibrio alginolyticus and Pseudomonas aeruginosa, but not the Gram-positive bacterium and fungus tested. Further phenoloxidase (PO) assay showed the rPtPLC could depress the crab proPO system activation in vitro, and lead to 72.8% inhibition of PO activity at the concentration of 9.11 μM. It also suppressed proPO activation induced by rPtcSP and rPtSPH1. As the first functional study of the recombinant PLC protein in crustaceans, the present results together indicate that PtPLC functions in the crab immune response possibly via inhibiting bacterial growth and regulating the proPO system.
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Affiliation(s)
- Yuan Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhaoxia Cui
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; National & Local Joint Engineering Laboratory for Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Guohui Shi
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Danli Luo
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuangyan Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chunlin Wang
- School of Marine Science, Ningbo University, Ningbo 315211, China
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Liu Y, Hou F, Wang X, Liu X. Recombinant expression and characterization of a serine protease inhibitor (Lvserpin7) from the Pacific white shrimp, Litopenaeus vannamei. FISH & SHELLFISH IMMUNOLOGY 2015; 42:256-263. [PMID: 25462553 DOI: 10.1016/j.fsi.2014.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/02/2014] [Accepted: 11/06/2014] [Indexed: 06/04/2023]
Abstract
Serine protease inhibitors (serpins) are widely known to its inhibitory role on proteases involved in the immune responses. Herein, a novel serine protease inhibitor (Lvserpin7), encoding for 411 amino acids with calculated molecular mass of 46.29 kDa and isoelectric point of 6.98 was characterized from the Pacific white shrimp Litopenaeus vannamei. Lvserpin7 shared 92.9% identities to Penaeus monodon serpin7. Among the tested tissues, Lvserpin7 was mainly expressed in hemocytes and gill. The expression profiles analysis indicated that Lvserpin7 was significantly up-regulated in the early stage upon Vibrio anguillarum, Micrococcus lysodeikticus or White Spot Syndrome Virus (WSSV) infection. Fusion protein expression was induced by IPTG, and the purified recombinant Lvserpin7 protein (rLvserpin7) binds to both the Gram-positive and Gram-negative bacteria. Also rLvserpin7 exhibited inhibitory activity against the proteases secreted by Bacillus subtilis. Moreover, rLvserpin7 showed inhibition role on prophenoloxidase activation. To recap, we proposed that Lvserpin7 was implicated in the shrimp immunity via the inhibition of bacterial proteases and proteases involved in prophenoloxidase system.
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Affiliation(s)
- Yongjie Liu
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Fujun Hou
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Xianzong Wang
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Xiaolin Liu
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China.
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Liu Y, Shi G, Cui Z, Luo D, Song C, Li X, Hui M, Li Y. PtSerpin from the swimming crab Portunus trituberculatus, a putative regulator of prophenoloxidase activation with antibacterial activity. FISH & SHELLFISH IMMUNOLOGY 2014; 39:365-371. [PMID: 24861890 DOI: 10.1016/j.fsi.2014.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 05/12/2014] [Accepted: 05/14/2014] [Indexed: 06/03/2023]
Abstract
Serpin or serine protease inhibitor is the largest family of protease inhibitors involved in many innate immune pathways, particularly the prophenoloxidase (proPO) activating system in arthropod. Here, we report the molecular and functional characterization of PtSerpin identified from the swimming crab Portunus trituberculatus. The genomic sequence encoding mature peptide of PtSerpin gene contained two exons of 84 and 1098 bp separated by one intron of 111 bp. The recombinant PtSerpin (rPtSerpin) with a predicted size of 44 kDa was expressed in Escherichia coli system, purified and assayed for its activities. The rPtSerpin exhibited inhibitory activity against trypsin in a dose-dependent manner, but did not affect chymotrypsin, which could define a role for PtSerpin as a trypsin inhibitor. The rPtSerpin could inhibit the growth of Gram-negative bacterium Vibrio alginolyticus, but not the tested Gram-positive bacterium and fungus. Further phenoloxidase (PO) assay showed PO activity was dramatically increased in hemocyte lysate supernatant of P. trituberculatus upon bacterial challenge. The rPtSerpin could depress the crab proPO system activation in vitro, and it could lead to 100% inhibition of PO activity under the concentration of 8.62 μM. Moreover, the rPtSerpin was able to inhibit the PO activity induced by rPtcSP and rPtSPH1. These results together indicate that PtSerpin is a potential trypsin inhibitor and may participate in crab innate immunity by the inhibition of bacterial growth and the regulation of proPO system.
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Affiliation(s)
- Yuan Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Guohui Shi
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Zhaoxia Cui
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; National & Local Joint Engineering Laboratory for Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
| | - Danli Luo
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Chengwen Song
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Xihong Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Min Hui
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Yingdong Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
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Wang Y, Lu Z, Jiang H. Manduca sexta proprophenoloxidase activating proteinase-3 (PAP3) stimulates melanization by activating proPAP3, proSPHs, and proPOs. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 50:82-91. [PMID: 24768974 PMCID: PMC4064829 DOI: 10.1016/j.ibmb.2014.04.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 04/09/2014] [Accepted: 04/10/2014] [Indexed: 05/22/2023]
Abstract
Melanization participates in various insect physiological processes including antimicrobial immune responses. Phenoloxidase (PO), a critical component of the enzyme system catalyzing melanin formation, is produced as an inactive precursor prophenoloxidase (proPO) and becomes active via specific proteolytic cleavage by proPO activating proteinase (PAP). In Manduca sexta, three PAPs can activate proPOs in the presence of two serine proteinase homologs (SPH1 and SPH2). While the hemolymph proteinases (HPs) that generate the active PAPs are known, it is unclear how the proSPHs (especially proSPH1) are activated. In this study, we isolated from plasma of bar-stage M. sexta larvae an Ile-Glu-Ala-Arg-p-nitroanilide hydrolyzing enzyme that cleaved the proSPHs. This proteinase, PAP3, generated active SPH1 and SPH2, which function as cofactors for PAP3 in proPO activation. Cleavage of the purified recombinant proSPHs by PAP3 yielded 38 kDa bands similar in mobility to the SPHs formed in vivo. Surprisingly, PAP3 also can activate proPAP3 to stimulate melanization in a direct positive feedback loop. The enhanced proPO activation concurred with the cleavage activation of proHP6, proHP8, proPAP1, proPAP3, proSPH1, proSPH2, proPOs, but not proHP14 or proHP21. These results indicate that PAP3, like PAP1, is a key factor of the self-reinforcing mechanism in the proPO activation system, which is linked to other immune responses in M. sexta.
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Affiliation(s)
- Yang Wang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Zhiqiang Lu
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA.
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Zhao YR, Xu YH, Jiang HS, Xu S, Zhao XF, Wang JX. Antibacterial activity of serine protease inhibitor 1 from kuruma shrimp Marsupenaeus japonicus. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 44:261-269. [PMID: 24412215 DOI: 10.1016/j.dci.2014.01.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/30/2013] [Accepted: 01/01/2014] [Indexed: 06/03/2023]
Abstract
Serine protease inhibitors (Serpins) are a large family of protease inhibitors involved in many critical biological processes such as blood coagulation, fibrinolysis, programmed cell death, development, and innate immunity. We identified MjSerp1, a serpin in the kuruma shrimp Marsupenaeus japonicus. The MjSerp1 cDNA has a 1239 bp open reading frame (ORF) that encodes a 412-amino acid protein with a 23 aa signal peptide and a classic serpin domain. MjSerp1 has a calculated molecular mass of 46.3 kDa and a predicted isoelectric point of 5.51. MjSerp1 is mainly expressed in the hepatopancreas and the intestines, and is moderately expressed in hemocytes. Expression pattern analysis indicated that MjSerp1 is upregulated in the hepatopancreas after Vibrio anguillarum challenge. rMjSerp1 inhibits three Gram-positive bacteria and two Gram-negative bacteria, but does not inhibit phenoloxidase activity. The microorganism binding assay showed that rMjSerp1 closely binds to both Gram-positive and Gram-negative bacteria. MjSerp1 also exhibits inhibitory activity against microbial serine proteases, such as subtilisin A and proteinase K, indicating that MjSerp1 acts as a microbial serine protease inhibitor. rMjSerp1 injection into shrimp enhances V. anguillarum clearance, but MjSerp1 knockdown through RNA interference impairs Vibrio clearance in vivo. These results indicate that MjSerp1 functions as a direct effector in the bacterial clearance of M. japonicus. All together, our findings provide novel evidences for the serine protease inhibitor in shrimp immunity.
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Affiliation(s)
- Yan-Ran Zhao
- MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China; Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China
| | - Yi-Hui Xu
- MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China; Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China
| | - Hai-Shan Jiang
- MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China; Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China
| | - Sen Xu
- MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China; Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China
| | - Xiao-Fan Zhao
- MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China; Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China
| | - Jin-Xing Wang
- MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China; Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
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RNAi-mediated knockdown of serine protease inhibitor genes increases the mortality of Plutella xylostella challenged by destruxin A. PLoS One 2014; 9:e97863. [PMID: 24837592 PMCID: PMC4023956 DOI: 10.1371/journal.pone.0097863] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 04/24/2014] [Indexed: 01/09/2023] Open
Abstract
Destruxin A is a mycotoxin that is secreted by entomopathogenic fungi which has a broad-spectrum insecticidal effect. Previous transcript and protein profiling analysis showed that destruxin A has significant effects on the expression of serine protease inhibitor genes (serpin-2, 4, 5) in the larvae of Plutella xylostella. In the current study, we aimed to understand the role of serpins under application of destruxin A. We obtained two full-length cDNA sequences of P. xylostella serpins, named serpin-4 and serpin-5, and cloned the serpin-2 gene whose full-length has already been published. Phylogenetic analysis indicated that these two serpin genes were highly clustered with other serpins associated with the immune response in other insects. The temporal and spatial expression of serpin-2, serpin-4 and serpin-5 were determined to be the highest in the fat body and hemolymph of 4th larval stage using qRT-PCR and western blot detection techniques. RNA interference (RNAi) mediated knockdown of P. xylostella serpin genes was carried out by microinjection of double-stranded RNA (dsRNA). The expression levels of serpins decreased significantly after RNAi. Results showed that the depletion of serpins induced cecropins expression, increased phenoloxidase (PO) activity, body melanization and mortality in the larvae of P. xylostella under the same lethal concentration of destruxin A. The superimposed effects of serpins RNAi were similar with the destruxin A treatment upon mortality of P. xylostella larvae. We discovered for the first time that serpins play indispensable role in P. xylostella when challenged by destruxin A and deduced the possible function mechanism of destruxin A. Our findings are conducive to fully understanding the potential insecticidal mechanism of destruxin A and constitute a well-defined potential molecular target for novel insecticides.
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Zhang X, Zheng Y, Jagadeeswaran G, Ren R, Sunkar R, Jiang H. Identification of conserved and novel microRNAs in Manduca sexta and their possible roles in the expression regulation of immunity-related genes. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 47:12-22. [PMID: 24508515 PMCID: PMC3992939 DOI: 10.1016/j.ibmb.2014.01.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 01/22/2014] [Accepted: 01/26/2014] [Indexed: 05/11/2023]
Abstract
The tobacco hornworm Manduca sexta has served as a model for insect biochemical and physiological research for decades. However, knowledge of the posttranscriptional regulation of gene expression by microRNAs is still rudimentary in this species. Our previous study (Zhang et al., 2012) identified 163 conserved and 13 novel microRNAs in M. sexta, most of which were present at low levels in pupae. To identify additional M. sexta microRNAs and more importantly to examine their possible roles in the expression regulation of immunity-related genes, we constructed four small RNA libraries using fat body and hemocytes from naïve or bacteria-injected larvae and obtained 32.9 million reads of 18-31 nucleotides by Illumina sequencing. Mse-miR-929 and mse-miR-1b (antisense microRNA of mse-miR-1) were predicted in the previous study and now found to be conserved microRNAs in the tissue samples. We also found four novel microRNAs, two of which result from a gene cluster. Mse-miR-281-star, mse-miR-965-star, mse-miR-31-star, and mse-miR-9b-star were present at higher levels than their respective mature strands. Abundance changes of microRNAs were observed after the immune challenge. Based on the quantitative data of mRNA levels in control and induced fat body and hemocytes as well as the results of microRNA target site prediction, we suggest that certain microRNAs and microRNA*s regulate gene expression for pattern recognition, prophenoloxidase activation, cellular responses, antimicrobial peptide synthesis, and conserved intracellular signal transduction (Toll, IMD, JAK-STAT, MAPK-JNK-p38, and small interfering RNA pathways). In summary, this study has enriched our knowledge on M. sexta microRNAs and how some of them may participate in the expression regulation of immunity-related genes.
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Affiliation(s)
- Xiufeng Zhang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA.
| | - Yun Zheng
- School of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China.
| | - Guru Jagadeeswaran
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA.
| | - Ren Ren
- School of Life Sciences, Fudan University, Shanghai 200433, China.
| | - Ramanjulu Sunkar
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA.
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA.
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Liu Y, Hou F, He S, Qian Z, Wang X, Mao A, Sun C, Liu X. Identification, characterization and functional analysis of a serine protease inhibitor (Lvserpin) from the Pacific white shrimp, Litopenaeus vannamei. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 43:35-46. [PMID: 24211341 DOI: 10.1016/j.dci.2013.10.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 10/24/2013] [Accepted: 10/25/2013] [Indexed: 06/02/2023]
Abstract
As important arthropod immune responses, prophenoloxidase (proPO) activation and Toll pathway initiation are mediated by serine proteinase cascades and regulated by serpins. Herein, a serine protease inhibitor (Lvserpin), encoding for 415 amino acids with calculated molecular weight of 46,639 Da and isoelectric point of 7.03 was characterized from the Pacific white shrimp Litopenaeus vannamei. Multiple sequence alignment revealed that Lvserpin shared the highest similarity with Penaeus monodon serpin6 (87%). Quantitative real-time PCR (qRT-PCR) results showed that the transcripts of Lvserpin were detected in all the examined tissues and most highly expressed in gill. The expression profiles of Lvserpin were greatly fluctuated upon infection of Vibrio anguillarum, Micrococcus lysoleikticus or White Spot Syndrome Virus (WSSV). Double stranded RNA-mediated suppression of Lvserpin resulted in a significant increase in the transcripts of two clip-domain serine proteinases (PPAE and PPAF), prophenoloxidase (proPO), anti-lipopolysaccharide factor (ALF), Crustin and penaeidin3 (Pens3) and also increased the high cumulative mortality post V. anguillarum injection. Besides, the recombinant Lvserpin protein (rLvserpin) was purified and exhibited inhibitory activity against trypsin. Also the rLvserpin showed inhibition on prophenoloxidase activation and bacterial growth. Hence, we proposed that the Lvserpin played important role in the shrimp innate immunity.
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Affiliation(s)
- Yongjie Liu
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Fujun Hou
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Shulin He
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Zhaoying Qian
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Xianzong Wang
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Aitao Mao
- Fisheries College, Guangdong Ocean University, Guangdong Zhanjiang 524025, China
| | - Chengbo Sun
- Fisheries College, Guangdong Ocean University, Guangdong Zhanjiang 524025, China
| | - Xiaolin Liu
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China.
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Wetsaphan N, Rimphanitchayakit V, Tassanakajon A, Somboonwiwat K. PmSERPIN3 from black tiger shrimp Penaeus monodon is capable of controlling the proPO system. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2013; 41:110-119. [PMID: 23660411 DOI: 10.1016/j.dci.2013.04.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/26/2013] [Accepted: 04/27/2013] [Indexed: 06/02/2023]
Abstract
Serpin or serine proteinase inhibitor is a family of protease inhibitors that are involved in controlling the proteolytic cascade in various biological processes. In shrimp, several serpins have been identified but only a few have been characterized. Herein, the PmSERPIN3 gene identified from Penaeus monodon EST database was studied. By using the 5'- and 3'-Rapid Amplification of cDNA Ends (RACE) techniques, the full-length of PmSERPIN3 cDNA was obtained. The cDNA contained an open reading frame of 1233 bp encoding for 410 amino acid residue protein. Genome sequence analysis revealed that the PmSERPIN3 was an intronless gene. RT-PCR analysis revealed that it was constitutively expressed in all developmental stages, all shrimp tissues tested, and upon pathogen infections. The recombinant mature PmSERPIN3 protein (rPmSERPIN3) produced in Escherichia coli exhibited inhibitory activity against subtilisin. The rPmSERPIN3 also inhibited the shrimp prophenoloxidase system activation in vitro. Injecting the rPmSERPIN3 along with Vibrio harveyi into the shrimp decreased the clearance rate of bacteria in the hemolymph. Potentially, the PmSERPIN3 functions as a regulator of the proPO activating system.
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Affiliation(s)
- Natthiya Wetsaphan
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
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Suwanchaichinda C, Ochieng R, Zhuang S, Kanost MR. Manduca sexta serpin-7, a putative regulator of hemolymph prophenoloxidase activation. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:555-61. [PMID: 23567587 PMCID: PMC3760416 DOI: 10.1016/j.ibmb.2013.03.015] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 03/22/2013] [Accepted: 03/26/2013] [Indexed: 05/09/2023]
Abstract
Serpins regulate various physiological reactions in humans and insects, including certain immune responses, primarily through inhibition of serine proteases. Six serpins have previously been identified and characterized in the tobacco hornworm Manduca sexta. In this study, we obtained a full-length cDNA sequence of another Manduca serpin, named serpin-7. The open reading frame of serpin-7 encodes a polypeptide of 400 amino acid residues with a predicted signal peptide of the first 15 residues. Multiple protein sequence alignment of the reactive center loop region of the M. sexta serpins indicated that serpin-7 contains Arg-Ile at the position of the predicted scissile bond cleaved by protease in the serpin inhibition mechanism. The same residues occur in the scissile bond of the reactive center loop in M. sexta serpin-4 and serpin-5, which are protease inhibitors that can block prophenoloxidase activation in plasma. Serpin-7 transcript was detected in hemocytes and fat body, and its expression increased in fat body after injection of larvae with Micrococcus luteus. Recombinant serpin-7 added to larval plasma inhibited spontaneous melanization and decreased prophenoloxidase activation stimulated by bacteria. Serpin-7 inhibited prophenoloxidase-activating protease-3 (PAP3), forming a stable serpin-protease complex. Considering that serpin-3 and serpin-6 are also efficient inhibitors of PAP3, it appears that multiple serpins present in plasma may have redundant or overlapping functions. We conclude that serpin-7 has serine protease inhibitory activity and is likely involved in regulation of proPO activation or other protease-mediated aspects of innate immunity in M. sexta.
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Affiliation(s)
| | | | | | - Michael R. Kanost
- Corresponding author. Tel.: +1 785 532 6964; fax: +1 785 532 7278. (M.R. Kanost)
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Ge ZY, Wan PJ, Cheng XF, Zhang Y, Li GQ, Han ZJ. Cloning and characterization of serpin-like genes from the striped rice stem borer, Chilo suppressalis. Genome 2013; 56:359-66. [DOI: 10.1139/gen-2013-0051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Serpins, also called serine proteinase inhibitors, are widely distributed in eukaryotes. In insects, serpins play important roles in regulating immune responses, gut physiology, and other processes. Here, we report the cloning and characterization of 12 serpin-like cDNAs from the striped rice stem borer (Chilo suppressalis), a major rice pest. The putative proteins share significant sequence similarity with known insect serpins, especially those from lepidopterons. Analysis of functional domains revealed that nine of the cloned serpins are putative trypsin- or chymotrypsin-like inhibitors; two are mixed-type serpins that may act as inhibitors for trypsins, elastases, or thrombin; and the remaining one is truncate. The potential functions of these serpins in interacting with host plants were also investigated by analyzing tissue-specific expression and the impact of different host plant genotypes on gene expression. Our results provide a foundation for future studies on the role of serpins in gut physiology in the striped rice stem borer, and also useful information for comparative analyses of serpins from different insect species.
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Affiliation(s)
- Zhao-Yu Ge
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, 1 Weigang Street, Nanjing 210095, China
| | - Pin-Jun Wan
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, 1 Weigang Street, Nanjing 210095, China
| | - Xiong-Feng Cheng
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, 1 Weigang Street, Nanjing 210095, China
| | - Yang Zhang
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, 1 Weigang Street, Nanjing 210095, China
| | - Guo-Qing Li
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, 1 Weigang Street, Nanjing 210095, China
| | - Zhao-Jun Han
- The Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, 1 Weigang Street, Nanjing 210095, China
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Clark KD, Strand MR. Hemolymph melanization in the silkmoth Bombyx mori involves formation of a high molecular mass complex that metabolizes tyrosine. J Biol Chem 2013; 288:14476-14487. [PMID: 23553628 DOI: 10.1074/jbc.m113.459222] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The phenoloxidase (PO) cascade regulates the melanization of blood (hemolymph) in insects and other arthropods. Most studies indicate that microbial elicitors activate the PO cascade, which results in processing of the zymogen PPO to PO. PO is then thought to oxidize tyrosine and o-diphenols to quinones, which leads to melanin. However, different lines of investigation raise questions as to whether these views are fully correct. Here we report that hemolymph from the silkmoth, Bombyx mori, rapidly melanizes after collection from a wound site. Prior studies indicated that in vitro activated PPO hydroxylates Tyr inefficiently. Measurement of in vivo substrate titers, however, suggested that Tyr was the only PO substrate initially present in B. mori plasma and that it is rapidly metabolized by PO. Fractionation of plasma by gel filtration chromatography followed by bioassays indicated that melanization activity was primarily associated with a high mass complex (~670 kDa) that contained PO. The prophenoloxidase-activating protease inhibitor Egf1.0 blocked formation of this complex and Tyr metabolism, but the addition of phenylthiourea to plasma before fractionation enhanced complex formation and Tyr metabolism. Mass spectrometry analysis indicated that the complex contained PO plus other proteins. Taken together, our results indicate that wounding alone activates the PO cascade in B. mori. They also suggest that complex formation is required for efficient use of Tyr as a substrate.
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Affiliation(s)
- Kevin D Clark
- Department of Entomology, University of Georgia, Athens, Georgia 30602.
| | - Michael R Strand
- Department of Entomology, University of Georgia, Athens, Georgia 30602.
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