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Haobo Jiang - One of the best experts on this subject based on the ideXlab platform.
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interaction of β 1 3 glucan with its recognition protein activates hemolymph proteinase 14 an initiation enzyme of the Prophenoloxidase activation system in manduca sexta
Journal of Biological Chemistry, 2006Co-Authors: Yang Wang, Haobo JiangAbstract:Abstract A serine proteinase pathway in insect hemolymph leads to Prophenoloxidase activation, an innate immune response against pathogen infection. In the tobacco hornworm Manduca sexta, recombinant hemolymph proteinase 14 precursor (pro-HP14) interacts with peptidoglycan, autoactivates, and initiates the proteinase cascade (Ji, C., Wang, Y., Guo, X., Hartson, S., and Jiang, H. (2004) J. Biol. Chem. 279, 34101–34106). Here, we report the purification and characterization of pro-HP14 from the hemolymph of bacteria-injected M. sexta larvae. The zymogen, consisting of a single polypeptide with a molecular mass of 68.5 kDa, is truncated at the amino terminus. It is converted to a two-chain active form in the presence of β-1,3-glucan (a fungal cell wall component) and β-1,3-glucan recognition protein-2. The 45-kDa heavy chain contains four low-density lipoprotein receptor A repeats, one Sushi domain, and one unique cysteine-rich region, whereas the 30-kDa light chain contains a serine proteinase domain, which was labeled by [3H]diisopropyl fluorophosphate. Pro-HP14 in the plasma strongly binds curdlan, zymosan, and yeast and interacts with peptidoglycan and Micrococcus luteus. Addition of autoactivated HP14 elevated phenoloxidase activity level in the larval plasma. Recombinant M. sexta serpin-1I reduced Prophenoloxidase activation by inhibiting HP14. These data are consistent with the current model on initiation and regulation of the Prophenoloxidase activation cascade upon recognition of pathogen-associated molecular patterns by specific pattern recognition proteins.
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A pattern recognition serine proteinase triggers the Prophenoloxidase activation cascade in the tobacco hornworm, Manduca sexta.
Journal of Biological Chemistry, 2004Co-Authors: Yang Wang, Xiaoping Guo, Steve Hartson, Haobo JiangAbstract:A serine proteinase cascade in insect hemolymph mediates Prophenoloxidase activation, a defense mechanism against pathogen or parasite infection. Little is known regarding its initiating proteinase or how this enzyme is activated in response to invading microorganisms. We have isolated from the tobacco hornworm, Manduca sexta, a cDNA encoding a modular protein designated hemolymph proteinase 14 (HP14). It contains five low density lipoprotein receptor class A repeats, a Sushi domain, a unique Cys-rich region, and a proteinase-catalytic domain. The HP14 mRNA exists in fat body and hemocytes of the naive larvae, and its level increases significantly at 24 h after a bacterial challenge. We expressed proHP14 with a carboxyl-terminal hexahistidine tag in a baculovirus/insect cell system and detected the recombinant protein in two forms. The 87-kDa protein was primarily intracellular, whereas the 75-kDa form was present in the medium. Interaction with peptidoglycan resulted in proteolytic processing of the purified zymogen and generation of an amidase activity. Supplementation of hemolymph with proHP14 greatly enhanced Prophenoloxidase activation in response to Micrococcus luteus. These data suggest that proHP14 is a pattern recognition protein that binds to bacteria and autoactivates and triggers the Prophenoloxidase activation system in the hemolymph of M. sexta.
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Nonproteolytic serine proteinase homologs are involved in Prophenoloxidase activation in the tobacco hornworm, Manduca sexta.
Insect biochemistry and molecular biology, 2003Co-Authors: Haobo Jiang, Yang Wang, Michael R. KanostAbstract:In insects, the Prophenoloxidase activation system is a defense mechanism against parasites and pathogens. Recognition of parasites or pathogens by pattern recognition receptors triggers activation of a serine proteinase cascade, leading to activation of Prophenoloxidase-activating proteinase (PAP). PAP converts inactive Prophenoloxidase (proPO) to active phenoloxidase (PO), which then catalyzes oxidation of phenolic compounds that can polymerize to form melanin. Because quinone intermediates and melanin are toxic to both hosts and pathogens, activation of proPO must be tightly regulated and localized. We report here purification and cDNA cloning of serine proteinase homologs (SPHs) from the tobacco hornworm, Manduca sexta, which interact with PAP-1 in proPO activation. Two SPHs were co-purified from plasma of M. sexta larvae with immulectin-2, a C-type lectin that binds to bacterial lipopolysaccharide. They contain an amino-terminal clip domain connected to a carboxyl-terminal serine proteinase-like domain. PAP-1 alone cannot efficiently activate proPO, but a mixture of SPHs and PAP-1 was much more effective for proPO activation. Immulectin-2, proPO and PAP-1 in hemolymph bound to the immobilized recombinant proteinase-like domain of SPH-1, indicating that a complex containing these proteins may exist in hemolymph. Since immulectin-2 is a pattern recognition receptor that binds to surface carbohydrates on pathogens, such a protein complex may localize activation of proPO on the surface of pathogens. SPH, which binds to immulectin-2, may function as a mediator to recruit proPO and PAP to the site of infection.
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Prophenoloxidase-activating Proteinase-2 from Hemolymph ofManduca sexta A BACTERIA-INDUCIBLE SERINE PROTEINASE CONTAINING TWO CLIP DOMAINS
The Journal of biological chemistry, 2002Co-Authors: Haobo Jiang, Yang Wang, Michael R. KanostAbstract:Abstract Proteolytic activation of Prophenoloxidase in insects is a component of the host defense system against invading pathogens and parasites. We have purified from hemolymph of the tobacco hornworm, Manduca sexta, a new serine proteinase that cleaves Prophenoloxidase. This enzyme, designated Prophenoloxidase-activating proteinase-2 (PAP-2), differs from another PAP, previously isolated from integuments of the same insect (PAP-1). PAP-2 contains two clip domains at its amino terminus and a catalytic domain at its carboxyl terminus, whereas PAP-1 has only one clip domain. Purified PAP-2 cleaved Prophenoloxidase at Arg51but yielded a product that has little phenoloxidase activity. However, in the presence of two serine proteinase homologs, active phenoloxidase was generated at a much higher level, and it formed covalently linked, high molecular weight oligomers. The serine proteinase homologs associate with a bacteria-binding lectin in M. sextahemolymph, indicating that they may be important for ensuring that the activation of Prophenoloxidase occurs only in the vicinity of invading microorganisms. PAP-2 mRNA was not detected in naive larval fat body or hemocytes, but it became abundant in these tissues after the insects were injected with bacteria.
Michael R. Kanost - One of the best experts on this subject based on the ideXlab platform.
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Manduca sexta serpin-7, a putative regulator of hemolymph Prophenoloxidase activation
Insect biochemistry and molecular biology, 2013Co-Authors: Chansak Suwanchaichinda, Rose Ochieng, Shufei Zhuang, Michael R. KanostAbstract: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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Nonproteolytic serine proteinase homologs are involved in Prophenoloxidase activation in the tobacco hornworm, Manduca sexta.
Insect biochemistry and molecular biology, 2003Co-Authors: Haobo Jiang, Yang Wang, Michael R. KanostAbstract:In insects, the Prophenoloxidase activation system is a defense mechanism against parasites and pathogens. Recognition of parasites or pathogens by pattern recognition receptors triggers activation of a serine proteinase cascade, leading to activation of Prophenoloxidase-activating proteinase (PAP). PAP converts inactive Prophenoloxidase (proPO) to active phenoloxidase (PO), which then catalyzes oxidation of phenolic compounds that can polymerize to form melanin. Because quinone intermediates and melanin are toxic to both hosts and pathogens, activation of proPO must be tightly regulated and localized. We report here purification and cDNA cloning of serine proteinase homologs (SPHs) from the tobacco hornworm, Manduca sexta, which interact with PAP-1 in proPO activation. Two SPHs were co-purified from plasma of M. sexta larvae with immulectin-2, a C-type lectin that binds to bacterial lipopolysaccharide. They contain an amino-terminal clip domain connected to a carboxyl-terminal serine proteinase-like domain. PAP-1 alone cannot efficiently activate proPO, but a mixture of SPHs and PAP-1 was much more effective for proPO activation. Immulectin-2, proPO and PAP-1 in hemolymph bound to the immobilized recombinant proteinase-like domain of SPH-1, indicating that a complex containing these proteins may exist in hemolymph. Since immulectin-2 is a pattern recognition receptor that binds to surface carbohydrates on pathogens, such a protein complex may localize activation of proPO on the surface of pathogens. SPH, which binds to immulectin-2, may function as a mediator to recruit proPO and PAP to the site of infection.
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Prophenoloxidase-activating Proteinase-2 from Hemolymph ofManduca sexta A BACTERIA-INDUCIBLE SERINE PROTEINASE CONTAINING TWO CLIP DOMAINS
The Journal of biological chemistry, 2002Co-Authors: Haobo Jiang, Yang Wang, Michael R. KanostAbstract:Abstract Proteolytic activation of Prophenoloxidase in insects is a component of the host defense system against invading pathogens and parasites. We have purified from hemolymph of the tobacco hornworm, Manduca sexta, a new serine proteinase that cleaves Prophenoloxidase. This enzyme, designated Prophenoloxidase-activating proteinase-2 (PAP-2), differs from another PAP, previously isolated from integuments of the same insect (PAP-1). PAP-2 contains two clip domains at its amino terminus and a catalytic domain at its carboxyl terminus, whereas PAP-1 has only one clip domain. Purified PAP-2 cleaved Prophenoloxidase at Arg51but yielded a product that has little phenoloxidase activity. However, in the presence of two serine proteinase homologs, active phenoloxidase was generated at a much higher level, and it formed covalently linked, high molecular weight oligomers. The serine proteinase homologs associate with a bacteria-binding lectin in M. sextahemolymph, indicating that they may be important for ensuring that the activation of Prophenoloxidase occurs only in the vicinity of invading microorganisms. PAP-2 mRNA was not detected in naive larval fat body or hemocytes, but it became abundant in these tissues after the insects were injected with bacteria.
Yang Wang - One of the best experts on this subject based on the ideXlab platform.
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interaction of β 1 3 glucan with its recognition protein activates hemolymph proteinase 14 an initiation enzyme of the Prophenoloxidase activation system in manduca sexta
Journal of Biological Chemistry, 2006Co-Authors: Yang Wang, Haobo JiangAbstract:Abstract A serine proteinase pathway in insect hemolymph leads to Prophenoloxidase activation, an innate immune response against pathogen infection. In the tobacco hornworm Manduca sexta, recombinant hemolymph proteinase 14 precursor (pro-HP14) interacts with peptidoglycan, autoactivates, and initiates the proteinase cascade (Ji, C., Wang, Y., Guo, X., Hartson, S., and Jiang, H. (2004) J. Biol. Chem. 279, 34101–34106). Here, we report the purification and characterization of pro-HP14 from the hemolymph of bacteria-injected M. sexta larvae. The zymogen, consisting of a single polypeptide with a molecular mass of 68.5 kDa, is truncated at the amino terminus. It is converted to a two-chain active form in the presence of β-1,3-glucan (a fungal cell wall component) and β-1,3-glucan recognition protein-2. The 45-kDa heavy chain contains four low-density lipoprotein receptor A repeats, one Sushi domain, and one unique cysteine-rich region, whereas the 30-kDa light chain contains a serine proteinase domain, which was labeled by [3H]diisopropyl fluorophosphate. Pro-HP14 in the plasma strongly binds curdlan, zymosan, and yeast and interacts with peptidoglycan and Micrococcus luteus. Addition of autoactivated HP14 elevated phenoloxidase activity level in the larval plasma. Recombinant M. sexta serpin-1I reduced Prophenoloxidase activation by inhibiting HP14. These data are consistent with the current model on initiation and regulation of the Prophenoloxidase activation cascade upon recognition of pathogen-associated molecular patterns by specific pattern recognition proteins.
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A pattern recognition serine proteinase triggers the Prophenoloxidase activation cascade in the tobacco hornworm, Manduca sexta.
Journal of Biological Chemistry, 2004Co-Authors: Yang Wang, Xiaoping Guo, Steve Hartson, Haobo JiangAbstract:A serine proteinase cascade in insect hemolymph mediates Prophenoloxidase activation, a defense mechanism against pathogen or parasite infection. Little is known regarding its initiating proteinase or how this enzyme is activated in response to invading microorganisms. We have isolated from the tobacco hornworm, Manduca sexta, a cDNA encoding a modular protein designated hemolymph proteinase 14 (HP14). It contains five low density lipoprotein receptor class A repeats, a Sushi domain, a unique Cys-rich region, and a proteinase-catalytic domain. The HP14 mRNA exists in fat body and hemocytes of the naive larvae, and its level increases significantly at 24 h after a bacterial challenge. We expressed proHP14 with a carboxyl-terminal hexahistidine tag in a baculovirus/insect cell system and detected the recombinant protein in two forms. The 87-kDa protein was primarily intracellular, whereas the 75-kDa form was present in the medium. Interaction with peptidoglycan resulted in proteolytic processing of the purified zymogen and generation of an amidase activity. Supplementation of hemolymph with proHP14 greatly enhanced Prophenoloxidase activation in response to Micrococcus luteus. These data suggest that proHP14 is a pattern recognition protein that binds to bacteria and autoactivates and triggers the Prophenoloxidase activation system in the hemolymph of M. sexta.
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Nonproteolytic serine proteinase homologs are involved in Prophenoloxidase activation in the tobacco hornworm, Manduca sexta.
Insect biochemistry and molecular biology, 2003Co-Authors: Haobo Jiang, Yang Wang, Michael R. KanostAbstract:In insects, the Prophenoloxidase activation system is a defense mechanism against parasites and pathogens. Recognition of parasites or pathogens by pattern recognition receptors triggers activation of a serine proteinase cascade, leading to activation of Prophenoloxidase-activating proteinase (PAP). PAP converts inactive Prophenoloxidase (proPO) to active phenoloxidase (PO), which then catalyzes oxidation of phenolic compounds that can polymerize to form melanin. Because quinone intermediates and melanin are toxic to both hosts and pathogens, activation of proPO must be tightly regulated and localized. We report here purification and cDNA cloning of serine proteinase homologs (SPHs) from the tobacco hornworm, Manduca sexta, which interact with PAP-1 in proPO activation. Two SPHs were co-purified from plasma of M. sexta larvae with immulectin-2, a C-type lectin that binds to bacterial lipopolysaccharide. They contain an amino-terminal clip domain connected to a carboxyl-terminal serine proteinase-like domain. PAP-1 alone cannot efficiently activate proPO, but a mixture of SPHs and PAP-1 was much more effective for proPO activation. Immulectin-2, proPO and PAP-1 in hemolymph bound to the immobilized recombinant proteinase-like domain of SPH-1, indicating that a complex containing these proteins may exist in hemolymph. Since immulectin-2 is a pattern recognition receptor that binds to surface carbohydrates on pathogens, such a protein complex may localize activation of proPO on the surface of pathogens. SPH, which binds to immulectin-2, may function as a mediator to recruit proPO and PAP to the site of infection.
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Prophenoloxidase-activating Proteinase-2 from Hemolymph ofManduca sexta A BACTERIA-INDUCIBLE SERINE PROTEINASE CONTAINING TWO CLIP DOMAINS
The Journal of biological chemistry, 2002Co-Authors: Haobo Jiang, Yang Wang, Michael R. KanostAbstract:Abstract Proteolytic activation of Prophenoloxidase in insects is a component of the host defense system against invading pathogens and parasites. We have purified from hemolymph of the tobacco hornworm, Manduca sexta, a new serine proteinase that cleaves Prophenoloxidase. This enzyme, designated Prophenoloxidase-activating proteinase-2 (PAP-2), differs from another PAP, previously isolated from integuments of the same insect (PAP-1). PAP-2 contains two clip domains at its amino terminus and a catalytic domain at its carboxyl terminus, whereas PAP-1 has only one clip domain. Purified PAP-2 cleaved Prophenoloxidase at Arg51but yielded a product that has little phenoloxidase activity. However, in the presence of two serine proteinase homologs, active phenoloxidase was generated at a much higher level, and it formed covalently linked, high molecular weight oligomers. The serine proteinase homologs associate with a bacteria-binding lectin in M. sextahemolymph, indicating that they may be important for ensuring that the activation of Prophenoloxidase occurs only in the vicinity of invading microorganisms. PAP-2 mRNA was not detected in naive larval fat body or hemocytes, but it became abundant in these tissues after the insects were injected with bacteria.
Kenneth Soderhall - One of the best experts on this subject based on the ideXlab platform.
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Prophenoloxidase-activating Enzyme
Handbook of Proteolytic Enzymes, 2013Co-Authors: Kenneth Soderhall, Anchalee Tassanakajon, Piti AmparyupAbstract:The third edition of the Handbook of Proteolytic Enzymes aims to be a comprehensive reference work for the enzymes that cleave proteins and peptides, and contains over 800 chapters. Each chapter is organized into sections describing the name and history, activity and specificity, structural chemistry, preparation, biological aspects, and distinguishing features for a specific peptidase. The subject of Chapter 676 is Prophenoloxidase-activating Enzyme.
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hindgut innate immunity and regulation of fecal microbiota through melanization in insects
Journal of Biological Chemistry, 2012Co-Authors: Qimiao Shao, Xuquan Li, Chengshu Wang, Zhiqiang Lu, Bing Yang, Yongping Huang, Kenneth Soderhall, Qiuyun Xu, Erjun LingAbstract:Many insects eat the green leaves of plants but excrete black feces in an as yet unknown mechanism. Insects cannot avoid ingesting pathogens with food that will be specifically detected by the midgut immune system. However, just as in mammals, many pathogens can still escape the insect midgut immune system and arrive in the hindgut, where they are excreted out with the feces. Here we show that the melanization of hindgut content induced by Prophenoloxidase, a key enzyme that induces the production of melanin around invaders and at wound sites, is the last line of immune defense to clear bacteria before feces excretion. We used the silkworm Bombyx mori as a model and found that Prophenoloxidase produced by hindgut cells is secreted into the hindgut contents. Several experiments were done to clearly demonstrate that the blackening of the insect feces was due to activated phenoloxidase, which served to regulate the number of bacteria in the hindgut. Our analysis of the silkworm hindgut Prophenoloxidase discloses the natural secret of why the phytophagous insect feces is black and provides insight into hindgut innate immunity, which is still rather unclear in mammals.
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phenoloxidase is an important component of the defense against aeromonas hydrophila infection in a crustacean pacifastacus leniusculus
Journal of Biological Chemistry, 2007Co-Authors: Haipeng Liu, Bok Luel Lee, Lage Cerenius, Irene Soderhall, Pikul Jiravanichpaisal, Kenneth SoderhallAbstract:The melanization cascade, in which phenoloxidase is the terminal enzyme, appears to play a key role in recognition of and defense against microbial infections in invertebrates. Here, we show that phenoloxidase activity and melanization are important for the immune defense toward a highly pathogenic bacterium, Aeromonas hydrophila, in the freshwater crayfish, Pacifastacus leniusculus. RNA interference-mediated depletion of crayfish Prophenoloxidase leads to increased bacterial growth, lower phagocytosis, lower phenoloxidase activity, lower nodule formation, and higher mortality when infected with this bacterium. In contrast, if RNA interference of pacifastin, an inhibitor of the crayfish Prophenoloxidase activation cascade, is performed, it results in lower bacterial growth, increased phagocytosis, increased nodule formation, higher phenoloxidase activity, and delayed mortality. Our data therefore suggest that phenoloxidase is required in crayfish defense against an infection by A. hydrophila, a highly virulent and pathogenic bacterium to crayfish.
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host Prophenoloxidase expression in freshwater crayfish is linked to increased resistance to the crayfish plague fungus aphanomyces astaci
Cellular Microbiology, 2003Co-Authors: Lage Cerenius, Eakaphun Bangyeekhun, Pia Keyser, Irene Soderhall, Kenneth SoderhallAbstract:Host Prophenoloxidase expression in freshwater crayfish is linked to increased resistance to the crayfish plague fungus, Aphanomyces astaci.
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a new easter type serine protease cleaves a masquerade like protein during Prophenoloxidase activation in holotrichia diomphalia larvae
Journal of Biological Chemistry, 2002Co-Authors: Moonsuk Kim, Kenneth Soderhall, Min Ji Baek, Mi Hee Lee, Jiwon Park, Soyoung Lee, Bok Luel LeeAbstract:Abstract The Prophenoloxidase (proPO) activation pathway, like the vertebrate complement system, consists of a protease cascade and functions as a non-self-recognition system in these animals. Determining the molecular mechanism by which pattern recognition molecules differentiate non-self from self and transduce signals that stimulate defense responses is a key for understanding the ways in which innate immune systems are regulated. However, the proPO system is poorly defined at the molecular level. The proPO-activating system of the insect Holotrichia diomphalia comprises several components, some of which have been cloned and characterized, such as the novel 27-kDa proPO-activating factor-III (PPAF-III) from the plasma of H. diomphalia larvae and two Prophenoloxidases. ThePPAF-III gene encodes an easter-type serine protease zymogen consisting of 351 amino acid residues with a mass of 40 kDa. The purified 27-kDa PPAF-III specifically cleaved a 55-kDa proPPAF-II to generate a 45-kDa PPAF-II with or without Ca2+ present. Furthermore, two Holotrichia Prophenoloxidases (proPO-I and -II) have been characterized, and their structural changes during activation were examined by in vitro reconstitution experiments. When the proPOs were incubated with PPAF-I, the 79-kDa proPOs were converted to 76-kDa proPOs, which did not exhibit any phenoloxidase (PO) activity. However, when the proPOs were incubated simultaneously with PPAF-I, proPPAF-II, and PPAF-III in the presence of Ca2+, a 60-kDa protein (PO-1) with PO activity was detected in addition to the 76-kDa proPO-II protein. These results indicate that the conversion of Holotrichia proPOs to enzymatically active phenoloxidase is accomplished by PPAF-I, PAF-II, and PPAF-III through a two-step limited proteolysis in the presence of Ca2+.
Paul T Brey - One of the best experts on this subject based on the ideXlab platform.
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Genomic structure and ecdysone regulation of the Prophenoloxidase 1 gene in the malaria vector Anopheles gambiae
Proceedings of the National Academy of Sciences of the United States of America, 1999Co-Authors: A Ahmed, David Martín, A. G. O. Manetti, Sung-jun Han, W.-j. Lee, Kostas D. Mathiopoulos, Hans-michael Müller, Fotis C. Kafatos, Alexander S. Raikhel, Paul T BreyAbstract:Prophenoloxidase, a melanin-synthesizing enzyme, is considered to be an important arthropod immune protein. In mosquitoes, Prophenoloxidase has been shown to be involved in refractory mechanisms against malaria parasites. In our study we used Anopheles gambiae, the most important human malaria vector, to characterize the first arthropod Prophenoloxidase gene at the genomic level. The complete nucleotide sequence, including the immediate 5′ flanking sequence (−855 bp) of the Prophenoloxidase 1 gene, was determined. The gene spans 10 kb and is composed of five exons and four introns coding for a 2.5-kb mRNA. In the 5′ flanking sequence, we found several putative regulatory motifs, two of which were identified as ecdysteroid regulatory elements. Electrophoretic mobility gel-shift assays and supershift assays demonstrated that the Aedes aegypti ecdysone receptor/Ultraspiracle nuclear receptor complex, and, seemingly, the endogenous Anopheles gambiae nuclear receptor complex, was able to bind one of the ecdysteroid response elements. Furthermore, 20-hydroxyecdysone stimulation was shown to up-regulate the transcription of the Prophenoloxidase 1 gene in an A. gambiae cell line.
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molecular cloning and chromosomal localization of a Prophenoloxidase cdna from the malaria vector anopheles gambiae
Insect Molecular Biology, 1998Co-Authors: A Ahmed, Masaaki Ashida, A Della Torre, A Kobayashi, Paul T BreyAbstract:A cDNA clone for Prophenoloxidase was isolated from the most important human malaria vector, Anopheles gambiae. The clone encoded a polypeptide of 79341 Da that contains the two copper binding domains common to all invertebrate Prophenoloxidases and haemocyanins. Expression of the Prophenoloxidase gene was detected throughout all life stages from egg to imago in two strains of A. gambiae; however, the strongest expression was observed in developing embryos in eggs. The Prophenoloxidase gene was mapped to the inversion rich region of the right arm of chromosome-2 in region 13B.
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Tyrosinase-type Prophenoloxidase distribution in the alimentary canal of strains of Anopheles gambiae refractory and susceptible to Plasmodium infection.
Experimental parasitology, 1995Co-Authors: Paul T Brey, Masaaki Ashida, A Ahmed, W.-j. Lee, M.j. LehaneAbstract:Abstract Tyrosinase-type Prophenoloxidase distribution was investigated in the posterior midgut and salivary glands of strains of noninfected adult Anopheles gambiae refractory (Blue strain) and susceptible (G3 strain) to infection with malaria parasites. Immunocytochemical localization showed that in the posterior midgut epithelium tyrosinase-type Prophenoloxidase was almost entirely restricted to apical granules. These are known to be a mixture of secretory grannies and lysosomes; it was not possible to distinguish between the two in this study. The secretory product in the lumen of the distal median lobe of the salivary gland was heavily labeled; the secretory product in the lumen of the distal lateral lobes was also labeled but to a lesser extent. Subjectively, no differences in the degree or pattern of labeling of either midgut or salivary glands between the strains of mosquito were apparent.
