scholarly journals Functional Characterization of a Venom Protein Calreticulin in the Ectoparasitoid Pachycrepoideus vindemiae

Insects ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 29 ◽  
Author(s):  
Lei Yang ◽  
Beibei Wang ◽  
Liming Qiu ◽  
Bin Wan ◽  
Yi Yang ◽  
...  
Keyword(s):  
Expression System ◽  
Functional Characterization ◽  
Venom Gland ◽  
Amino Acid Identity ◽  
Immunohistochemical Localization ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Venom Protein ◽  
Pupal Parasitoids ◽  
Venom Proteins

Venom proteins act in the immunological interactions between parasitoids and their host insects. The effect of venom proteins on host immunity is not fully understood in pupal parasitoids. We identified the functions of a venom protein, calreticulin (PvCRT), in the pupal ectoparasitoid Pachycrepoideus vindemiae. Here, we report that PvCRT features a signal peptide and two conserved “calreticulin” domains. Multiple sequence alignments show that PvCRT shares 83.54% amino acid identity with CRT from both Pteromalus puparum and Nasonia vitripennis, which infers a close relationship among these three species. Using qPCR analysis, we found a lower expression level of PvCRT (0.27-fold) in the venom apparatus compared to the corresponding carcass. Immunohistochemical localization revealed that PvCRT was ubiquitously expressed in venom gland. The expression of the PvCRT gene in Drosophila transgenic lines via the UAS/Gal4 binary expression system reduced the self-encapsulation phenotype of tu(1)Sz1 mutants. Additionally, studies on humoral immunity indicate that PvCRT does not affect the antimicrobial immune responses of the host. This work on an ectoparasitoid will increase our understanding of venom–mediated host-parasitoid interactions.

scholarly journals Leukocyte Immunoglobulin-Like Receptors A2 and A6 are Expressed in Avian Macrophages and Modulate Cytokine Production by Activating Multiple Signaling Pathways

2018 ◽  
Vol 19 (9) ◽  
pp. 2710 ◽  
Author(s):  
Anh Truong ◽  
Deivendran Rengaraj ◽  
Yeojin Hong ◽  
Ha Tran ◽  
Hoang Dang ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Antigen Processing ◽  
Functional Characterization ◽  
Adaptive Immune System ◽  
Mapk Signaling ◽  
Immune Functions ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Mammalian Proteins ◽  
Close Relationship

The activating leukocyte immunoglobulin-like receptors (LILRAs) play an important role in innate immunity. However, most of the LILRA members have not been characterized in avian species including chickens. The present study is the first attempt at cloning, structural analysis and functional characterization of two LILRAs (LILRA2 and LILRA6) in chickens. Multiple sequence alignments and construction of a phylogenetic tree of chicken LILRA2 and LILRA6 with mammalian proteins revealed high conservation between chicken LILRA2 and LILRA6 and a close relationship between the chicken and mammalian proteins. The mRNA expression of LILRA2 and LILRA6 was high in chicken HD11 macrophages and the small intestine compared to that in several other tissues and cells tested. To examine the function of LILRA2 and LILRA6 in chicken immunity, LILRA2 and LILRA6 were transfected into HD11 cells. Our findings indicated that LILRA2 and LILRA6 are associated with the phosphorylation of Src kinases and SHP2, which play a regulatory role in immune functions. Moreover, LILRA6 associated with and activated MHC class I, β2-microglobulin and induced the expression of transporters associated with antigen processing but LILRA2 did not. Furthermore, both LILRA2 and LILRA6 activated JAK-STAT, NF-κB, PI3K/AKT and ERK1/2 MAPK signaling pathways and induced Th1-, Th2- and Th17-type cytokines and Toll-like receptors. Collectively, this study indicates that LILRA2 and LILRA6 are essential for macrophage-mediated immune responses and they have the potential to complement the innate and adaptive immune system against pathogens.

scholarly journals Comparative venom gland transcriptomics ofNaja kaouthia(monocled cobra) from Malaysia and Thailand: elucidating geographical venom variation and insights into sequence novelty

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3142 ◽  
Author(s):  
Kae Yi Tan ◽  
Choo Hock Tan ◽  
Lawan Chanhome ◽  
Nget Hong Tan
Keyword(s):  
Expression Patterns ◽  
Gene Families ◽  
Venom Gland ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Sequence Alignments ◽  
Illumina Hiseq ◽  
Multiple Sequence ◽  
Toxin Genes ◽  
Transcriptional Pattern

BackgroundThe monocled cobra (Naja kaouthia) is a medically important venomous snake in Southeast Asia. Its venom has been shown to vary geographically in relation to venom composition and neurotoxic activity, indicating vast diversity of the toxin genes within the species. To investigate the polygenic trait of the venom and its locale-specific variation, we profiled and compared the venom gland transcriptomes ofN. kaouthiafrom Malaysia (NK-M) and Thailand (NK-T) applying next-generation sequencing (NGS) technology.MethodsThe transcriptomes were sequenced on the Illumina HiSeq platform, assembled and followed by transcript clustering and annotations for gene expression and function. Pairwise or multiple sequence alignments were conducted on the toxin genes expressed. Substitution rates were studied for the major toxins co-expressed in NK-M and NK-T.Results and discussionThe toxin transcripts showed high redundancy (41–82% of the total mRNA expression) and comprised 23 gene families expressed in NK-M and NK-T, respectively (22 gene families were co-expressed). Among the venom genes, three-finger toxins (3FTxs) predominated in the expression, with multiple sequences noted. Comparative analysis and selection study revealed that 3FTxs are genetically conserved between the geographical specimens whilst demonstrating distinct differential expression patterns, implying gene up-regulation for selected principal toxins, or alternatively, enhanced transcript degradation or lack of transcription of certain traits. One of the striking features that elucidates the inter-geographical venom variation is the up-regulation of α-neurotoxins (constitutes ∼80.0% of toxin’s fragments per kilobase of exon model per million mapped reads (FPKM)), particularly the long-chain α-elapitoxin-Nk2a (48.3%) in NK-T but only 1.7% was noted in NK-M. Instead, short neurotoxin isoforms were up-regulated in NK-M (46.4%). Another distinct transcriptional pattern observed is the exclusively and abundantly expressed cytotoxin CTX-3 in NK-T. The findings suggested correlation with the geographical variation in proteome and toxicity of the venom, and support the call for optimising antivenom production and use in the region. Besides, the current study uncovered full and partial sequences of numerous toxin genes fromN. kaouthiawhich have not been reported hitherto; these includeN. kaouthia-specificl-amino acid oxidase (LAAO), snake venom serine protease (SVSP), cystatin, acetylcholinesterase (AChE), hyaluronidase (HYA), waprin, phospholipase B (PLB), aminopeptidase (AP), neprilysin, etc. Taken together, the findings further enrich the snake toxin database and provide deeper insights into the genetic diversity of cobra venom toxins.

scholarly journals Sulphonation of dehydroepiandrosterone and neurosteroids: molecular cloning, expression, and functional characterization of a novel zebrafish SULT2 cytosolic sulphotransferase

2003 ◽  
Vol 375 (3) ◽  
pp. 785-791 ◽  
Author(s):  
Takuya SUGAHARA ◽  
Yuh-Shyong YANG ◽  
Chau-Ching LIU ◽  
T. Govind PAI ◽  
Ming-Cheh LIU
Keyword(s):  
Molecular Cloning ◽  
Expressed Sequence Tag ◽  
Expression System ◽  
Functional Characterization ◽  
Amino Acid Identity ◽  
Cdna Clones ◽  
Reverse Transcription Pcr ◽  
Prokaryotic Expression System ◽  
Partial Cdna

By searching the zebrafish EST (expressed-sequence tag) database, we have identified two partial cDNA clones encoding the 5′ and 3′ regions of a putative zebrafish sulphotransferase (ST). Using the reverse transcription-PCR technique, a full-length cDNA encoding this zebrafish ST was successfully cloned. Sequence analysis revealed that this novel zebrafish ST displays 44%, 43% and 40% amino acid identity with mouse SULT2B1, human SULT2B1b and human SULT2A1 ST respectively. This zebrafish ST therefore appears to belong to the SULT2 cytosolic ST gene family. Recombinant zebrafish ST, expressed using the pGEX-2TK prokaryotic expression system and purified from transformed Escherichia coli cells, migrated as a 34 kDa protein upon SDS/PAGE. Purified zebrafish ST displayed a strong sulphonating activity toward DHEA (dehydroepiandrosterone), with a optimum pH of 9.5. The enzyme also exhibited activities toward several neurosteroids with differential Km and Vmax values. A thermostability experiment revealed the enzyme to be relatively stable over a temperature range between 20 °C and 43 °C. Among ten different divalent metal cations tested, Fe2+ and Cd2+ exhibited small, but significant, stimulatory effects, whereas Hg2+ and Cu2+ displayed considerably stronger inhibitory effects on the DHEA-sulphonating activity of the enzyme. These results constitute the first study on the molecular cloning, expression, and characterization of a zebrafish cytosolic SULT2 ST.

scholarly journals Identification, cloning, expression and functional characterization of an astacin-like metalloprotease toxin from Loxosceles intermedia (brown spider) venom

2007 ◽  
Vol 406 (2) ◽  
pp. 355-363 ◽  
Author(s):  
Rafael B. da Silveira ◽  
Ana C. M. Wille ◽  
Olga M. Chaim ◽  
Marcia H. Appel ◽  
Dilza T. Silva ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Venom Gland ◽  
Cross Reactivity ◽  
Polyclonal Antiserum ◽  
Venom Protein ◽  
Functional Studies ◽  
Brown Spider ◽  
Endothelial Cell Cultures ◽  
And Function

Injuries caused by brown spiders (Loxosceles genus) are associated with dermonecrotic lesions with gravitational spreading and systemic manifestations. The venom has a complex composition containing many different toxins, of which metalloproteases have been described in many different species of this genus. These toxins may degrade extracellular matrix constituents acting as a spreading factor. By using a cDNA library from an Loxosceles intermedia venom gland, we cloned and expressed a 900 bp cDNA, which encoded a signal peptide and a propeptide, which corresponded to a 30 kDa metalloprotease, now named LALP (Loxosceles astacin-like protease). Recombinant LALP was refolded and used to produce a polyclonal antiserum, which showed cross-reactivity with a 29 kDa native venom protein. CD analysis provided evidence that the recombinant LALP toxin was folded correctly, was still in a native conformation and had not aggregated. LALP addition to endothelial cell cultures resulted in de-adhesion of the cells, and also in the degradation of fibronectin and fibrinogen (this could be inhibited by the presence of the bivalent chelator 1,10-phenanthroline) and of gelatin in vitro. Sequence comparison (nucleotide and deduced amino acid), phylogenetic analysis and analysis of the functional recombinant toxin revealed that LALP is related in both structure and function to the astacin family of metalloproteases. This suggests that an astacin-like toxin is present in a animal venom secretion and indicates that recombinant LALP will be a useful tool for future structural and functional studies on venom and the astacin family.

scholarly journals Positive natural selection in primate genes of the type I interferon response

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elena N. Judd ◽  
Alison R. Gilchrist ◽  
Nicholas R. Meyerson ◽  
Sara L. Sawyer
Keyword(s):  
Natural Selection ◽  
Positive Selection ◽  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Multiple Sequence Alignments ◽  
Interferon Stimulated Genes ◽  
Interferon Induction

Abstract Background The Type I interferon response is an important first-line defense against viruses. In turn, viruses antagonize (i.e., degrade, mis-localize, etc.) many proteins in interferon pathways. Thus, hosts and viruses are locked in an evolutionary arms race for dominance of the Type I interferon pathway. As a result, many genes in interferon pathways have experienced positive natural selection in favor of new allelic forms that can better recognize viruses or escape viral antagonists. Here, we performed a holistic analysis of selective pressures acting on genes in the Type I interferon family. We initially hypothesized that the genes responsible for inducing the production of interferon would be antagonized more heavily by viruses than genes that are turned on as a result of interferon. Our logic was that viruses would have greater effect if they worked upstream of the production of interferon molecules because, once interferon is produced, hundreds of interferon-stimulated proteins would activate and the virus would need to counteract them one-by-one. Results We curated multiple sequence alignments of primate orthologs for 131 genes active in interferon production and signaling (herein, “induction” genes), 100 interferon-stimulated genes, and 100 randomly chosen genes. We analyzed each multiple sequence alignment for the signatures of recurrent positive selection. Counter to our hypothesis, we found the interferon-stimulated genes, and not interferon induction genes, are evolving significantly more rapidly than a random set of genes. Interferon induction genes evolve in a way that is indistinguishable from a matched set of random genes (22% and 18% of genes bear signatures of positive selection, respectively). In contrast, interferon-stimulated genes evolve differently, with 33% of genes evolving under positive selection and containing a significantly higher fraction of codons that have experienced selection for recurrent replacement of the encoded amino acid. Conclusion Viruses may antagonize individual products of the interferon response more often than trying to neutralize the system altogether.

scholarly journals Harnessing a Transient Gene Expression System in Nicotiana benthamiana to Explore Plant Agrochemical Transporters

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 524
Author(s):  
Bingqi Wu ◽  
Zhiting Chen ◽  
Xiaohui Xu ◽  
Ronghua Chen ◽  
Siwei Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transient Expression ◽  
Nicotiana Benthamiana ◽  
Heterologous Gene Expression ◽  
Expression System ◽  
Functional Characterization ◽  
Transient Gene Expression ◽  
High Mobility ◽  
Gene Expression System

Functional characterization of plant agrichemical transporters provided an opportunity to discover molecules that have a high mobility in plants and have the potential to increase the amount of pesticides reaching damage sites. Agrobacterium-mediated transient expression in tobacco is simple and fast, and its protein expression efficiency is high; this system is generally used to mediate heterologous gene expression. In this article, transient expression of tobacco nicotine uptake permease (NtNUP1) and rice polyamine uptake transporter 1 (OsPUT1) in Nicotiana benthamiana was performed to investigate whether this system is useful as a platform for studying the interactions between plant transporters and pesticides. The results showed that NtNUP1 increases nicotine uptake in N. benthamiana foliar discs and protoplasts, indicating that this transient gene expression system is feasible for studying gene function. Moreover, yeast expression of OsPUT1 apparently increases methomyl uptake. Overall, this method of constructing a transient gene expression system is useful for improving the efficiency of analyzing the functions of plant heterologous transporter-encoding genes and revealed that this system can be further used to study the functions of transporters and pesticides, especially their interactions.

scholarly journals Respiratory syncytial virus B sequence analysis reveals a novel early genotype

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juan C. Muñoz-Escalante ◽  
Andreu Comas-García ◽  
Sofía Bernal-Silva ◽  
Daniel E. Noyola
Keyword(s):  
Molecular Markers ◽  
Respiratory Syncytial Virus ◽  
Maximum Likelihood ◽  
Respiratory Infections ◽  
Phylogenetic Analyses ◽  
Detection Methods ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Individual Gene ◽  
Syncytial Virus

AbstractRespiratory syncytial virus (RSV) is a major cause of respiratory infections and is classified in two main groups, RSV-A and RSV-B, with multiple genotypes within each of them. For RSV-B, more than 30 genotypes have been described, without consensus on their definition. The lack of genotype assignation criteria has a direct impact on viral evolution understanding, development of viral detection methods as well as vaccines design. Here we analyzed the totality of complete RSV-B G gene ectodomain sequences published in GenBank until September 2018 (n = 2190) including 478 complete genome sequences using maximum likelihood and Bayesian phylogenetic analyses, as well as intergenotypic and intragenotypic distance matrices, in order to generate a systematic genotype assignation. Individual RSV-B genes were also assessed using maximum likelihood phylogenetic analyses and multiple sequence alignments were used to identify molecular markers associated to specific genotypes. Analyses of the complete G gene ectodomain region, sequences clustering patterns, and the presence of molecular markers of each individual gene indicate that the 37 previously described genotypes can be classified into fifteen distinct genotypes: BA, BA-C, BA-CC, CB1-THB, GB1-GB4, GB6, JAB1-NZB2, SAB1, SAB2, SAB4, URU2 and a novel early circulating genotype characterized in the present study and designated GB0.

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