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1.
Gene ; 763: 144956, 2020 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-32739586

RESUMO

Sox transcription factors play essential roles in a variety of critical physiological processes. Still, members of the sox gene family have not yet been genome-wide identified in shrimps. In this study, a total of five members of the sox gene family were identified from the genome of Pacific white shrimp Litopenaeus vannamei and classified into three subgroups based on the conserved HMG-box domain. Among them, three belong to the SoxB subgroup (one in B1 and two in B2), one in the SoxC subgroup, and one in the SoxE subgroup. The five sox genes had different sex-biased expression in some tissues. Sox21, soxB1, and sox14 had a higher expression in ovary than in testis. In comparison, sox4 had a male-biased specific expression in the gonad, hepatopancreas, gill, and eyestalk. There was no difference in soxE gene expression between testis and ovary. During embryonic development, the expression level of three sox genes (soxB1, sox21, and soxE) was higher in gastrulation stage compared to previous stages, declined in limb bud stage and then increased in intramembrane nauplius stage; the expression of sox4 was detected in blastula stage and continued to increase in the following two stages and then surged in intramembrane nauplius stage; the highest expression of sox14 was in the fertilized egg stage, and the expression level decreased with the development of the embryo. These results suggest that the shrimp sox gene family may be involved in gametogenesis, tridermogenesis, and neurogenesis.


Assuntos
Proteínas de Artrópodes/genética , Penaeidae/genética , Fatores de Transcrição SOX/genética , Animais , Proteínas de Artrópodes/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Brânquias/embriologia , Brânquias/metabolismo , Hepatopâncreas/embriologia , Hepatopâncreas/metabolismo , Masculino , Especificidade de Órgãos , Ovário/embriologia , Ovário/metabolismo , Penaeidae/embriologia , Fatores de Transcrição SOX/metabolismo , Testículo/embriologia , Testículo/metabolismo
2.
Parasitol Res ; 119(9): 3013-3022, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32740752

RESUMO

Babesiosis is a tick-borne protozoonosis caused by Babesia, which can cause fever, hemolytic anemia, hemoglobinuria, and even death. Babesia microti is a parasite found in rodents and can be pathogenic to humans. In this study, the full-length cDNA of a B. microti cysteine protease (BmCYP) was expressed and the recombinant rBmCYP protein analyzed and characterized. BmCYP is encoded by an ORF of 1.3 kb, with a predicted molecular weight of 50 kDa and a theoretical pI of 8.5. The amino acid sequence of BmCYP exhibits an identity of 32.9 to 35.2% with cysteine proteases of Babesia ovis, Babesia bovis, and Theileria, respectively. The results of the proteinase assays show that rBmCYP has cysteine protease enzymatic activity. In addition, we demonstrate that tick cystatins rRhcyst-1 and rRhcyst-2 were able to effectively inhibit the activity of rBmCYP; the inhibition rates were 57.2% and 30.9%, respectively. Tick cystatins Rhcyst-1 and Rhcyst-2 were differentially expressed in ticks that fed on Babesia-infected mice relative to non-infected control ticks. Our results suggest that BmCYP is a functional enzyme with cysteine protease enzymatic activity and may be involved in tick-B. microti interactions.


Assuntos
Proteínas de Artrópodes/metabolismo , Babesia microti/enzimologia , Cistatinas/metabolismo , Cisteína Proteases/metabolismo , Proteínas de Protozoários/metabolismo , Carrapatos/metabolismo , Carrapatos/parasitologia , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/genética , Babesia bovis/química , Babesia bovis/enzimologia , Babesia bovis/genética , Babesia microti/química , Babesia microti/genética , Babesiose/parasitologia , Cistatinas/genética , Cisteína Proteases/química , Cisteína Proteases/genética , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Ligação Proteica , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Carrapatos/genética
3.
Korean J Parasitol ; 58(2): 161-171, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32418385

RESUMO

The ticks feed large amount of blood from their hosts and transmit pathogens to the victims. The salivary gland plays an important role in the blood feeding. When the female ticks are near engorgement, the salivary gland gradually loses its functions and begins to rapidly degenerate. In this study, data-independent acquisition quantitative proteomics was used to study changes in the phosphorylation modification of proteins during salivary gland degeneration in Haemaphysalis longicornis. In this quantitative study, 400 phosphorylated proteins and 850 phosphorylation modification sites were identified. Trough RNA interference experiments, we found that among the proteins with changes in phosphorylation, apoptosis-promoting Hippo protein played a role in salivary gland degeneration.


Assuntos
Proteínas de Artrópodes/metabolismo , Regeneração , Glândulas Salivares/fisiologia , Animais , Apoptose , Proteínas de Drosophila , Feminino , Peptídeos e Proteínas de Sinalização Intracelular , Fosforilação , Proteínas Serina-Treonina Quinases
4.
Proc Natl Acad Sci U S A ; 117(23): 12657-12664, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32461364

RESUMO

Blood-feeding arthropods produce antiinflammatory salivary proteins called evasins that function through inhibition of chemokine-receptor signaling in the host. Herein, we show that the evasin ACA-01 from the Amblyomma cajennense tick can be posttranslationally sulfated at two tyrosine residues, albeit as a mixture of sulfated variants. Homogenously sulfated variants of the proteins were efficiently assembled via a semisynthetic native chemical ligation strategy. Sulfation significantly improved the binding affinity of ACA-01 for a range of proinflammatory chemokines and enhanced the ability of ACA-01 to inhibit chemokine signaling through cognate receptors. Comparisons of evasin sequences and structural data suggest that tyrosine sulfation serves as a receptor mimetic strategy for recognizing and suppressing the proinflammatory activity of a wide variety of mammalian chemokines. As such, the incorporation of this posttranslational modification (PTM) or mimics thereof into evasins may provide a strategy to optimize tick salivary proteins for antiinflammatory applications.


Assuntos
Ácaros e Carrapatos/metabolismo , Proteínas de Artrópodes/metabolismo , Quimiocinas/antagonistas & inibidores , Processamento de Proteína Pós-Traducional , Saliva/metabolismo , Animais , Proteínas de Artrópodes/química , Quimiocinas/metabolismo , Células HEK293 , Humanos , Ligação Proteica , Sulfatos/metabolismo , Tirosina/metabolismo
5.
Toxicon ; 179: 21-32, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32126222

RESUMO

Centruroides hirsutipalpus (Scorpiones: Buthidae) is related to the "striped scorpion" group inhabiting the western Pacific region of Mexico. Human accidents caused by this species are medically important due to the great number of people stung and the severity of the resulting intoxication. This communication reports an extensive venom characterization using high-throughput proteomic and Illumina transcriptomic sequencing performed with RNA purified from its venom glands. 2,553,529 reads were assembled into 44,579 transcripts. From these transcripts, 23,880 were successfully annoted using Trinotate. Using specialized databases and by performing bioinformatic searches, it was possible to identify 147 putative venom protein transcripts. These include α- and ß-type sodium channel toxins (NaScTx), potassium channel toxins (KScTx) (α-, ß-, δ-, γ- and λ-types), enzymes (metalloproteases, hyaluronidases, phospholipases, serine proteases, and monooxygenases), protease inhibitors, host defense peptides (HDPs) such as defensins, non-disulfide bridge peptides (NDBPs), anionic peptides, superfamily CAP proteins, insulin growth factor-binding proteins (IGFBPs), orphan peptides, and other venom components (La1 peptides). De novo tandem mass spectrometric sequencing of digested venom identificatied 50 peptides. The venom of C. hirsutipalpus contains the highest reported number (77) of transcripts encoding NaScTxs, which are the components responsible for human fatalities.


Assuntos
Venenos de Escorpião/química , Escorpiões , Animais , Proteínas de Artrópodes/metabolismo , Glândulas Exócrinas , Sequenciamento de Nucleotídeos em Larga Escala , México , Proteoma/metabolismo , Proteômica , Venenos de Escorpião/metabolismo , Transcriptoma/fisiologia
6.
Insect Biochem Mol Biol ; 120: 103347, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32114158

RESUMO

The use of CRISPR-Cas9 has revolutionized functional genetic work in many organisms, including more and more insect species. However, successful gene editing or genetic transformation has not yet been reported for chelicerates, the second largest group of terrestrial animals. Within this group, some mite and tick species are economically very important for agriculture and human health, and the availability of a gene-editing tool would be a significant advancement for the field. Here, we report on the use of CRISPR-Cas9 in the spider mite Tetranychus urticae. The ovary of virgin adult females was injected with a mix of Cas9 and sgRNAs targeting the phytoene desaturase gene. Natural mutants of this laterally transferred gene have previously shown an easy-to-score albino phenotype. Albino sons of injected virgin females were mated with wild-type females, and two independent transformed lines where created and further characterized. Albinism inherited as a recessive monogenic trait. Sequencing of the complete target-gene of both lines revealed two different lesions at expected locations near the PAM site in the target-gene. Both lines did not genetically complement each other in dedicated crosses, nor when crossed to a reference albino strain with a known genetic defect in the same gene. In conclusion, two independent mutagenesis events were induced in the spider mite T. urticae using CRISPR-Cas9, hereby providing proof-of-concept that CRISPR-Cas9 can be used to create gene knockouts in mites.


Assuntos
Proteínas de Artrópodes/genética , Sistemas CRISPR-Cas , Edição de Genes , Mutagênese , Oxirredutases/genética , Tetranychidae/genética , Animais , Proteínas de Artrópodes/metabolismo , Oxirredutases/metabolismo
7.
Vet Parasitol ; 279: 109064, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32143012

RESUMO

Tick serpins are involved in enzyme activity, food digestion, blood-feeding, immune response and anticoagulation. Little is known about the potential roles of serpins in tick reproduction. RHS8, a serpin from the tick Rhipicephalus haemaphysaloides, has an open reading frame 1212 bp long and encodes a protein that has 404 amino acids and a predicted molecular weight of 45 kDa. RHS8 exhibits 89.58 % amino acid identity with RmS15 in Rhipicephalus microplus. RHS8 was expressed primarily in larvae and nymphs. RHS8 mRNA expression in the ovaries, fat bodies and salivary glands were up-regulated from feeding to ovipositing ticks. RNAi results showed that RHS8 dsRNA-injected ticks had a lower body weight, longer feeding time, fewer eggs laid and lower egg hatchability. Tick reproduction, such as egg laying and hatching, was disrupted by RNAi. Compared with the control group, ovaries of the RHS8 interference group were light brown color, indicating a reduction in yolk granule accumulation. Western blot results showed that the expression of RHVg3 and RHVg4 proteins in ovaries was reduced in the RHS8 dsRNA-injected group. These results indicate that RHS8 is related to tick reproduction and its interference affects vitellogenesis.


Assuntos
Proteínas de Artrópodes/genética , Rhipicephalus/fisiologia , Serpinas/genética , Vitelogênese/genética , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/metabolismo , Feminino , Larva/crescimento & desenvolvimento , Larva/fisiologia , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Filogenia , Interferência de RNA , Rhipicephalus/genética , Rhipicephalus/crescimento & desenvolvimento , Alinhamento de Sequência , Serpinas/química , Serpinas/metabolismo
8.
PLoS Negl Trop Dis ; 14(2): e0007758, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32049966

RESUMO

Amblyomma americanum ticks transmit more than a third of human tick-borne disease (TBD) agents in the United States. Tick saliva proteins are critical to success of ticks as vectors of TBD agents, and thus might serve as targets in tick antigen-based vaccines to prevent TBD infections. We describe a systems biology approach to identify, by LC-MS/MS, saliva proteins (tick = 1182, rabbit = 335) that A. americanum ticks likely inject into the host every 24 h during the first 8 days of feeding, and towards the end of feeding. Searching against entries in GenBank grouped tick and rabbit proteins into 27 and 25 functional categories. Aside from housekeeping-like proteins, majority of tick saliva proteins belong to the tick-specific (no homology to non-tick organisms: 32%), protease inhibitors (13%), proteases (8%), glycine-rich proteins (6%) and lipocalins (4%) categories. Global secretion dynamics analysis suggests that majority (74%) of proteins in this study are associated with regulating initial tick feeding functions and transmission of pathogens as they are secreted within 24-48 h of tick attachment. Comparative analysis of the A. americanum tick saliva proteome to five other tick saliva proteomes identified 284 conserved tick saliva proteins: we speculate that these regulate critical tick feeding functions and might serve as tick vaccine antigens. We discuss our findings in the context of understanding A. americanum tick feeding physiology as a means through which we can find effective targets for a vaccine against tick feeding.


Assuntos
Proteínas de Artrópodes/química , Ixodidae/fisiologia , Proteoma/química , Saliva/química , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Cromatografia Líquida , Comportamento Alimentar , Feminino , Ixodidae/química , Ixodidae/genética , Masculino , Proteoma/genética , Proteoma/metabolismo , Coelhos , Saliva/metabolismo , Proteínas e Peptídeos Salivares/química , Proteínas e Peptídeos Salivares/genética , Proteínas e Peptídeos Salivares/metabolismo , Espectrometria de Massas em Tandem , Infestações por Carrapato/parasitologia
9.
J Therm Biol ; 87: 102477, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32001020

RESUMO

Temperature is a critical abiotic factor that causes physiological changes in arthropods. However, little is known about the effect of heat stress on the antioxidant responses of Araneae species. Hylyphantes graminicola is a dominant predator in many cropping systems in China. In the present study, the effect of short-term heat stress (36, 38, 40 or 42 °C) on the reactive oxygen species (ROS) levels, the activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], peroxidases [POD] and glutathione-S-transferases GST]), total antioxidant capacity (TAC), malondialdehyde (MDA) concentrations and survival of H. graminicola spiderlings and adults were investigated. The results showed that H. graminicola adults had a significantly higher survival rate compared to spiderlings at 40 °C. The heat stress increased ROS contents in H. graminicola. The SOD, CAT, POD and GST activities increased in spiderlings and adults under heat stress. These data suggest a defensive function for these enzymes in alleviating oxidative damage. Specifically, SOD plays a key role in reducing the high level of superoxide radicals in spiderlings and adults. Moreover, the POD and CAT capabilities for scavenging H2O2 in spiderlings were similar, and CAT may play a more important role than POD in scavenging H2O2 in adults at 42 °C. The spiderling TAC increased significantly at 40 and 42 °C, and the adult TAC was stable at 36-40 °C but decreased at 42 °C. These data suggest that TAC was insufficient in H. graminicola adults under more severe stress conditions. These results further our understanding of the physiological response of Araneae species exposed to heat stress.


Assuntos
Resposta ao Choque Térmico , Espécies Reativas de Oxigênio/metabolismo , Aranhas/metabolismo , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Catalase/genética , Catalase/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Peroxidases/genética , Peroxidases/metabolismo , Aranhas/fisiologia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
10.
Vet Parasitol ; 279: 109043, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32070900

RESUMO

Dermacentor marginatus is one of the main tick species in northwestern China, and is a vector of various tick-borne pathogens. Tick control method largely depends on chemical agents, but the disadvantages of using such approach would cause environmental damage and the risk of developing tick resistance to acaricides. Vaccination of tick protective antigen is an eco-friendly approach which is an alternative and promising method to mitigate tick infestation in livestock. In the study, a mu-class glutathione S-transferase (GST) sequence of D. marginatus was cloned and the recombinant protein (rDmGST) was expressed. Transcriptional level of the GST was measured together with native GST activity of the tick. Finally, A vaccine trial on rabbits against D. marginatus was proceeded to evaluate the anti-tick effect of rDmGST. Results reveled that the CDs of the D. margiantus glutathione S-transferase mu 1 gene has 669 base pair nucleotide sequence encoding a 223 amino acid. The deduced GST protein sequence had over 95 % similarity with that of D. variabilis. The rDmGST was efficiently expressed soluble and purified by His trap affinity chromatography. Enzyme activity of native GST and transcriptional profiles of the GST showed up-regulation in different stages and organs of D. marginaus during blood feeding. Polyclonal antibody reacted with rDmGST in Western blotting. Tick challenge on rDmGST inoculated rabbits showed reductions in adult female engorgement rate, total egg mass and egg hatching rate with an overall vaccine efficacy of 43.69 %. The results of the experiment indicated the GST has potential value to be an effective protective antigen of D. marginatus.


Assuntos
Antígenos/análise , Proteínas de Artrópodes/genética , Dermacentor/efeitos dos fármacos , Dermacentor/genética , Glutationa Transferase/genética , Controle de Ácaros e Carrapatos , Infestações por Carrapato/veterinária , Vacinas/imunologia , Animais , Proteínas de Artrópodes/metabolismo , Feminino , Glutationa Transferase/metabolismo , Coelhos , Infestações por Carrapato/prevenção & controle
11.
Parasit Vectors ; 13(1): 105, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32103780

RESUMO

BACKGROUND: Anaplasma ovis is a gram-negative, tick-borne obligate intraerythrocytic pathogen, which causes ovine anaplasmosis in small ruminants worldwide. VirB10 of A. ovis is an integral component of the Type IV Secretion System (T4SS). The T4SS is used by bacteria to transfer DNA and/or proteins undeviatingly into the host cell to increase their virulence. To more thoroughly understand the interaction between A. ovis and Dermacentor silvarum, a vector containing the virb10 gene of A. ovis was used as a bait plasmid to screen interacting proteins from the cDNA library of the D. silvarum salivary gland using the yeast two-hybrid system. METHODS: The cDNA of the D. silvarum salivary gland was cloned into the pGADT7-SmaI vector (prey plasmid) to construct the yeast two-hybrid cDNA library. The virb10 gene was cloned into the pGBKT7 vector to generate a bait plasmid. Any gene auto-activation or toxicity effects in the yeast strain Y2HGold were excluded. The screening was performed by combining the bait and prey plasmids in yeast strains to identify positive preys. The positive preys were then sequenced, and the obtained sequences were subjected to further analyses using Gene Ontology, UniProt, SMART, and STRING. Additionally, the interaction between the bait and the prey was evaluated using the glutathione S-transferase (GST) pull-down assay. RESULTS: A total of two clones were obtained from the cDNA library using the yeast two-hybrid system, and the sequence analysis showed that both clones encoded the same large tegument protein, UL36. Furthermore, the proteins GST-UL36 and His-VirB10 were successfully expressed in vitro and the interaction between the two proteins was successfully demonstrated by the GST pull-down assay. CONCLUSIONS: To our knowledge, this study is the first to screen for D. silvarum salivary gland proteins that interact with A. ovis VirB10. The resulting candidate, UL36, is a multi-functional protein. Further investigations into the functionality of UL36 should be carried out, which might help in identifying novel prevention and treatment strategies for A. ovis infection. The present study provides a base for exploring and further understanding the interactions between A. ovis and D. silvarum.


Assuntos
Anaplasma ovis/metabolismo , Proteínas de Artrópodes/metabolismo , Proteínas de Bactérias/metabolismo , Dermacentor/metabolismo , Dermacentor/microbiologia , Sistemas de Secreção Tipo IV/metabolismo , Anaplasma ovis/genética , Animais , Proteínas de Artrópodes/genética , Proteínas de Bactérias/genética , Dermacentor/genética , Interações Hospedeiro-Parasita , Ligação Proteica , Glândulas Salivares/metabolismo , Glândulas Salivares/microbiologia , Técnicas do Sistema de Duplo-Híbrido , Sistemas de Secreção Tipo IV/genética
12.
Artigo em Inglês | MEDLINE | ID: mdl-31958500

RESUMO

Elongation of very long-chain fatty acid 4 (Elovl4) proteins participate in the biosynthesis of long-chain and very long-chain polyunsaturated fatty acids (LC-PUFA and VLC-PUFA). In the present study, an elovl4 cDNA was cloned from the swimming crab Portunus trituberculatus by PCR techniques and functionally characterized using recombinant expression in yeast Saccharomyces cerevisiae. The elovl4 cDNA sequence contained an open reading frame of 1038 base pairs, encoding a protein of 346 amino acids. The elovl4 has typical Elovl structures, with transmembrane domains (6) and a histidine box. The elovl4 was expressed in various tissues analyzed, with the highest expression found in intestine and hepatopancreas, followed by stomach and eyestalk. The functional characterization of Elovl4 yeast showed that the P. trituberculatus Elovl4 can elongate C18-22 polyunsaturated fatty acids (PUFA), reaching in some cases products of C24 and C26. Along its ability to elongate PUFA, the P. trituberculatus Elovl4 was also efficient in the elongation of saturated fatty acids, with 28:0 and 30:0 being prominent elongation products. These results provide insight into the LC-PUFA biosynthetic capability of commercially important species of crustaceans.


Assuntos
Proteínas de Artrópodes/genética , Braquiúros/genética , Elongases de Ácidos Graxos/genética , Ácidos Graxos Insaturados/biossíntese , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/metabolismo , Braquiúros/enzimologia , Braquiúros/metabolismo , Clonagem Molecular , Elongases de Ácidos Graxos/metabolismo , Filogenia , Homologia de Sequência de Aminoácidos
13.
Exp Appl Acarol ; 80(3): 349-361, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31927645

RESUMO

Apyrase is one of the essential platelet aggregation inhibitors in hematophagous arthropods due to its ability to hydrolyze ATP and ADP molecules. Here, an apyrase (TNapyrase) with antiplatelet aggregation activity was purified and characterized from the nymphs of the camel tick Hyalomma dromedarii through anion exchange and gel filtration columns. The homogeneity of TNapyrase was confirmed by native-PAGE, SDS-PAGE as well as with isoelectric focusing. Purified TNapyrase had a molecular mass of 25 kDa and a monomer structure. TNapyrase hydrolyzed various nucleotides in the order of ATP > PPi > ADP > UDP > 6GP. The Km value was 1.25 mM ATP and its optimum activity reached at pH 8.4. The influence of various ions on TNapyrase activity showed that FeCl2, FeCl3 and ZnCl2 are activators of TNapyrase. EDTA inhibited TNapyrase activity competitively with a single binding site on the molecule and Ki value of 2 mM. Finally, TNapyrase caused 70% inhibition of ADP-stimulated platelets aggregation and is a possible target for antibodies in future tick vaccine studies.


Assuntos
Apirase/metabolismo , Proteínas de Artrópodes/metabolismo , Agregação Plaquetária , Carrapatos/enzimologia , Animais , Camelus , Ninfa
14.
Artigo em Inglês | MEDLINE | ID: mdl-31647988

RESUMO

This review discusses the reaction catalysed, and the structure and function of the cellulase, endo-ß-1,4-glucanase and the hemicellulase enzymes, ß-1,3-glucanase and endo-ß-1,4-mannase that are present in numerous invertebrate groups with a diverse range of feeding specialisations. These range from microbial deposit and filter feeders, micro and macrophagous algal feeders, omnivores to herbivorous leaf litter and wood feeders. Endo-ß-1,4-glucanase from glycosyl hydrolase family 9 (GH9) digests cellulose like ß-1,4-glucans from a range of materials. As it hydrolyses crystalline cellulose very slowly, it is a poor cellulase. Where tested, the enzyme has dual endo-ß-1,4-glucanase and lichenase activity. Its presence does not necessarily indicate the ability of an animal to digest cellulose. It only indicates the ability to digest ß-1,4-glucans and its function, which is discussed in this review, should be considered with reference to the substrates present in the diet. ß-1,3-glucanase (laminarinase) belongs to glycosyl hydrolase family 16 (GH16) and hydrolyses ß-1.3-glucans. These polysaccharides are present in the cell walls of algae, protozoans and yeast, and they also occur as storage polysaccharides within protozoans and algae. Depending on their site of expression, these enzymes may function as a digestive enzyme or may be involved in innate immunity. Enzymes present in the digestive fluids or tissues, would be digestive. Haemolymph GH16 proteins may be involved in innate immunity through the activation of the phenol oxidase system. Insect GH16 proteins expressed within the haemolymph have lost their catalytic residues and function as ß-glucan binding proteins. In contrast, crustacean GH16 proteins expressed within the same tissue, have retained the catalytic residues and thus possibly their ß-1,3-glucanase activity. The potential function of which is discussed. Endo-ß-1,4-mannase from glycosyl hydrolase family 5, subfamily 10 (GH5_10) hydrolyses mannan, glucomannan and galactomannan. These hemicelluloses are present in the cell walls of plants and algae and also function as storage polysaccharides within legume and palm seeds. They are digestive enzymes whose high expression in some species suggests they are a major contributor to hemicellulose digestion. They may also provide the animal with substantial amounts of monosaccharides for energy.


Assuntos
Proteínas de Artrópodes , Celulase , Glicosídeo Hidrolases , Invertebrados , Filogenia , Polissacarídeos/metabolismo , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Celulase/genética , Celulase/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Invertebrados/enzimologia , Invertebrados/genética
15.
Fish Shellfish Immunol ; 96: 53-61, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31801694

RESUMO

Target of rapamycin (TOR) is an atypical of Ser/Thr protein kinase that plays an important role in many aspects such as cell growth, reproduction, differentiation, cell cycle regulation, autophagy and apoptosis. However, little information is known about the enzyme in crustaceans. Here, a novel TOR was identified from shrimp Penaeus vannamei (PvTOR) and its biological functions were investigated in response low temperature stress. The PvTOR gene encoded a polypeptide of 2464 amino acids with an estimated molecular mass of 279.4 kD and a predicted isoelectronic point (pI) of 7.30. Phylogenetic analysis revealed that PvTOR shared high similarity with other known species. PvTOR mRNA was detected in all the tested tissues and highest transcription in muscle and hepatopancreas. PvTOR transcriptional level was up-regulated significantly at 1.5 h and 3 h, and down-regulated at 12 h and 24 h after low temperature stress. TEM and autophagy indicator system GFP-PvLC3 suggested that low temperature induced autophagy generation. ROS, Ca2+ concentration and apoptosis rate were increased significantly in TOR-knockdown shrimp after low temperature stress. The autophagy associated gene ATG8II/I, PvBeclin-1, PvATG14, apoptosis gene PvPARP, Pvcasp-3, PvBAX and Pvp53 transcripts, and casp-3/8 activity in hemocyte were increased significantly in TOR-knockdown group shrimp at 3 h after low temperature stress. Additionally, THC counts of TOR-knockdown group were significantly higher than the dsGFP group. In summary, these results suggested that PvTOR plays an important role in the adaptation mechanisms of shrimp at low temperature by regulating autophagy and apoptosis.


Assuntos
Proteínas de Artrópodes/genética , Temperatura Baixa/efeitos adversos , Penaeidae/genética , Penaeidae/imunologia , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/genética , Animais , Apoptose/genética , Proteínas de Artrópodes/metabolismo , Autofagia/genética , Filogenia , Análise de Sequência de DNA , Estresse Fisiológico , Serina-Treonina Quinases TOR/metabolismo
16.
Artigo em Inglês | MEDLINE | ID: mdl-31629811

RESUMO

Prohibitin (PHB) is an evolutionarily conserved multifunctional protein with ubiquitous expression. In this study, we cloned the PHB gene from the testis of the swimming crab Portunus trituberculatus (PtPHB) and analyzed the deduced amino acid sequence. The expression level of phb mRNA in larvae was analyzed using qRT-PCR. The expression level of phb mRNA and PHB protein in different tissues were analyzed using qRT-PCR and Western blot respectively. Enzyme-linked immunosorbent assay analyses of the PHB protein were conducted with the testis and ovaries from P. trituberculatus specimens at different developmental stages. PHB was localized with mitochondria and ubiquitin in the testis and ovaries. The PtPHB gene was found to contain an open reading frame of 825 bp, encoding a predicted peptide with 275 amino acids, sharing between 65.9% and 96.7% similarity with that of other species. The qRT-PCR and Western blot results showed that the phb gene and PHB protein both expressed less in the testis and ovary than in other tissues, and the phb gene presented the lowest expression in the Z1 stage. Furthermore, the phb gene and PHB protein expression were different in the testis and ovaries at different developmental stages. PHB was mainly found to be co-localized with mitochondria and ubiquitin in cytoplasm and acrosome complex during spermatogenesis and in follicular cells during oogenesis. Interestingly, PHB-mitochondria signals and ubiquitin signal were also found in oocytes. These results indicated that PHB might play important roles during spermatogenesis and oogenesis by regulating mitochondrial activities.


Assuntos
Proteínas de Artrópodes/metabolismo , Braquiúros/metabolismo , Oogênese/fisiologia , Ovário/metabolismo , Proteínas Repressoras/metabolismo , Espermatogênese/fisiologia , Testículo/metabolismo , Animais , Feminino , Masculino , Mitocôndrias/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-31683012

RESUMO

The mud crab, Scylla paramamosain, is an economically-important crab in China. Air exposure is an important environmental stressor during mud crab culture and transportation. Adaptive mechanisms responding to air exposure in mud crabs are still poorly understood. In this study, mud crabs were exposed to air for 120 h. Air exposure decreased total hemocyte counts, led to cytological damage, and caused high mortality. Transcriptomic analysis was conducted at 0, 6 and 96 h after air exposure. A total of 3530 differentially expressed genes (DEGs) were identified. DEGs were mainly involved in the oxidative stress response, metabolism, cellular processes, signal transduction, and immune functions. Transcriptomic analysis also revealed that genes of glycolysis and of the tricarboxylic acid cycle were key factors in regulating the mud crab adaptation to air exposure.


Assuntos
Adaptação Fisiológica/genética , Ar , Aquicultura , Braquiúros/genética , Braquiúros/ultraestrutura , Hepatopâncreas/patologia , Estresse Oxidativo/genética , Transcriptoma , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Braquiúros/metabolismo , China , Perfilação da Expressão Gênica , Glicólise/genética , Hemócitos/patologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-31846692

RESUMO

The oriental river prawn, Macrobrachium nipponense, is a commercial freshwater prawn species in China. It is highly sensitive to hypoxia, and this has posed a challenge to its intensive culturing. To date, the effects of hypoxia on reproduction in female prawns are not entirely clear, as are the underlying mechanisms of the effects of hypoxia. In this work, comparative transcriptome and gene expression analyses of the eyestalk were performed in M. nipponense females under hypoxia and reoxygenation conditions. Sequencing and de novo assembly of the combined reads yielded 43,583 unigenes with an average length of 1726 bp. A total of 711 genes were found to be differentially expressed in the eyestalk under the hypoxia and reoxygenation conditions. With the help of functional and pathway enrichment analysis of the differentially expressed genes, a novel set of transcripts that were associated with several important functions, such as hormone biosynthesis and progesterone-mediated oocyte maturation, were identified. Additionally, ten neuropeptides were identified based on the differentially expressed transcripts, and they were validated by quantitative real-time polymerase chain reaction (qRT-PCR) and reverse transcription PCR (RT-PCR) analyses. Three neuropeptide genes were expressed in the neural tissue and ovary of the prawns; this indicates that they were involved in reproductive processes. In particular, RNA interference (RNAi) short neuropeptide F dramatically promoted ovary maturation, as indicated by the gonad somatic index. While the present findings do indicate that hypoxia affects reproductive function in M. nipponense females, in-depth functional analyses of the candidate neuropeptides should be conducted in the future to understand their role in hypoxia adaptation and the associated mechanisms that affect the reproductive capacity of this species.


Assuntos
Palaemonidae/genética , Palaemonidae/metabolismo , Animais , Proteínas de Artrópodes/metabolismo , Olho/metabolismo , Feminino , Hipóxia/metabolismo , Neuropeptídeos/metabolismo , Oxigênio/administração & dosagem , Oxigênio/metabolismo , Palaemonidae/efeitos dos fármacos , Transcriptoma
19.
Arch Biochem Biophys ; 680: 108228, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31843643

RESUMO

Myosin II molecules in the thick filaments of striated muscle form a structure in which the heads interact with each other and fold back onto the tail. This structure, the "interacting heads motif" (IHM), provides a mechanistic basis for the auto-inhibition of myosin in relaxed thick filaments. Similar IHM interactions occur in single myosin molecules of smooth and nonmuscle cells in the switched-off state. In addition to the interaction between the two heads, which inhibits their activity, the IHM also contains an interaction between the motor domain of one head and the initial part (subfragment 2, S2) of the tail. This is thought to be a crucial anchoring interaction that holds the IHM in place on the thick filament. S2 appears to cross the head at a specific location within a broader region of the motor domain known as the myosin mesa. Here, we show that the positive and negative charge distribution in this part of the mesa is complementary to the charge distribution on S2. We have designated this the "mesa trail" owing to its linear path across the mesa. We studied the structural sequence alignment, the location of charged residues on the surface of myosin head atomic models, and the distribution of surface charge potential along the mesa trail in different types of myosin II and in different species. The charge distribution in both the mesa trail and the adjacent S2 is relatively conserved. This suggests a common basis for IHM formation across different myosin IIs, dependent on attraction between complementary charged patches on S2 and the myosin head. Conservation from mammals to insects suggests that the mesa trail/S2 interaction plays a key role in the inhibitory function of the IHM.


Assuntos
Miosina Tipo II/metabolismo , Animais , Aracnídeos/química , Aracnídeos/metabolismo , Proteínas de Artrópodes/química , Proteínas de Artrópodes/metabolismo , Dictyostelium/química , Dictyostelium/metabolismo , Insetos , Mamíferos , Modelos Moleculares , Miosina Tipo II/química , Domínios e Motivos de Interação entre Proteínas , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Especificidade da Espécie
20.
Proc Natl Acad Sci U S A ; 117(1): 362-370, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31871188

RESUMO

The complement system is a crucial part of innate immune defenses against invading pathogens. The blood-meal of the tick Rhipicephalus pulchellus lasts for days, and the tick must therefore rely on inhibitors to counter complement activation. We have identified a class of inhibitors from tick saliva, the CirpT family, and generated detailed structural data revealing their mechanism of action. We show direct binding of a CirpT to complement C5 and have determined the structure of the C5-CirpT complex by cryoelectron microscopy. This reveals an interaction with the peripheral macro globulin domain 4 (C5_MG4) of C5. To achieve higher resolution detail, the structure of the C5_MG4-CirpT complex was solved by X-ray crystallography (at 2.7 Å). We thus present the fold of the CirpT protein family, and provide detailed mechanistic insights into its inhibitory function. Analysis of the binding interface reveals a mechanism of C5 inhibition, and provides information to expand our biological understanding of the activation of C5, and thus the terminal complement pathway.


Assuntos
Proteínas de Artrópodes/imunologia , Ativação do Complemento/imunologia , Complemento C5/antagonistas & inibidores , Imunidade Inata , Rhipicephalus/imunologia , Animais , Proteínas de Artrópodes/metabolismo , Proteínas de Artrópodes/ultraestrutura , Complemento C5/imunologia , Complemento C5/ultraestrutura , Microscopia Crioeletrônica , Cristalografia por Raios X , Eritrócitos/imunologia , Comportamento Alimentar , Feminino , Cobaias , Hemólise/imunologia , Humanos , Masculino , Ligação Proteica/imunologia , Domínios Proteicos/imunologia , Coelhos , Ratos , Rhipicephalus/metabolismo , Saliva/imunologia , Saliva/metabolismo , Ovinos
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