A serine proteinase homolog venom protein from an endoparasitoid wasp inhibits melanization of the host hemolymph

Asgari, Sassan; Zhang, Guangmei; Zareie, Reza; Schmidt, Otto

doi:10.1016/s0965-1748(03)00116-4

Cited by 147 publications

(132 citation statements)

References 31 publications

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“…We synthesized dsRNA specific to Bro11 (HvAV-3e orf98; 350 bp) and GFP (500 bp) sequences by in vitro transcription. In cleavage assays, 100 ng of Bro11 and GFP dsRNAs were incubated with 0.3 pmol of purified RNase III, as well as a control protein (Vn50) (2) in the presence of a catalysis buffer containing Mg 2ϩ . Vn50 also contained a His tag and was produced and purified from Sf9 cells.…”

Section: Resultsmentioning

confidence: 99%

“…The dsRNA substrates were incubated with 0.3 pmol of purified RNase III and Vn50 (control) proteins expressed by recombinant baculoviruses. Vn50 is a venom protein from the Cotesia rubecula parasitoid wasp with similarity to serine protease homologs, but it lacks any enzyme activity (2). A cleavage assay was performed at 37°C for 0, 10, 20, 30, 45, and 60 min of incubation in cleavage buffer (100 mM NaCl, 10 mM MgCl 2 , 20 mM HEPES [pH 8.0], 5 mM dithiothreitol, 1 mM EDTA, 0.1% Triton X-100, 20% glycerol).…”

Section: Cell Cultures and Virus Infectionmentioning

confidence: 99%

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An Ascovirus-Encoded RNase III Autoregulates Its Expression and Suppresses RNA Interference-Mediated Gene Silencing

Hussain

Abraham

Asgari

2010

J Virol

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RNase III proteins play vital roles in processing of several types of RNA molecules and gene silencing. Recently, it has been discovered that some plant and animal viruses encode RNase III-like proteins as well. Genome sequencing of four virus species belonging to the Ascoviridae family has revealed sequence conservation of an RNase III open reading frame among the viruses. These have not been explored in ascoviruses, and therefore their role in host-virus interaction is unknown. Here, we confirmed expression of Heliothis virescens ascovirus (HvAV-3e) open reading frame 27 (orf27) that encodes an RNase III-like protein after infection and demonstrated dsRNA specific endoribonuclease activity of the encoded protein. Analysis of the expression patterns of orf27 in virus-infected insect cells and a bacterial expression system revealed autoregulation of this protein over time. Moreover, HvAV-3e RNase III was found essential for virus DNA replication and infection using RNA interference (RNAi)-mediated gene silencing. In addition, using green fluorescent protein gene as a marker, we provide evidence that RNase III is involved in the suppression of gene silencing. To our knowledge, this is the first insect virus-encoded RNase III described and shown to suppress host cell RNAi defense mechanism.

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Section: Resultsmentioning

confidence: 99%

Section: Cell Cultures and Virus Infectionmentioning

confidence: 99%

An Ascovirus-Encoded RNase III Autoregulates Its Expression and Suppresses RNA Interference-Mediated Gene Silencing

Hussain

Abraham

Asgari

2010

J Virol

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“…function. Virulence proteins include serine proteinase homolog (24,49) and unrelated peptide Vn 4.6 (22) from Cotesia rubecula venom, extracellular superoxide dismutase (25) and serpin (23) from Leptopilina boulardi venom, and epidermal growth factor-like proteins (26,48,52) from Microplitis demolitor PDV. With an estimated 600,000 species, parasitoid wasps are one of the most abundant and diverse insect groups on earth (53).…”

Section: Discussionmentioning

confidence: 99%

“…Inhibition of melanization is particularly important as this is a common mechanism for encapsulating and killing parasitoid eggs (19 -21). Possibly because of the very small sizes of parasitoids, a limited number of components from their virulence factors have been identified and characterized (22)(23)(24)(25)(26).…”

mentioning

confidence: 99%

A Venom Serpin Splicing Isoform of the Endoparasitoid Wasp Pteromalus puparum Suppresses Host Prophenoloxidase Cascade by Forming Complexes with Host Hemolymph Proteinases

Yan

Fang

Liu

et al. 2017

Journal of Biological Chemistry

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Edited by Charles E. SamuelTo ensure successful parasitism, parasitoid wasps inject venom along with their eggs into their hosts. The venom serves to suppress host immune responses, including melanization. Venom from Pteromalus puparum, a pupal endoparasitoid, inhibits melanization of host hemolymph in vitro in a dose-dependent manner. Using assay-guided fractionation, a serpin splicing isoform with phenoloxidase inhibitory activity was identified as P. puparum serpin-1, venom isoform (PpS1V). This serpin gene has 16 predicted splicing isoforms that differ only in the C-terminal region. RT-PCR results show that the specific serpin isoform is differentially expressed in the venom gland. Recombinant PpS1V (rPpS1V) suppresses host prophenoloxidase (PPO) activation rather than inhibiting the phenoloxidase directly. Pulldown assays show that PpS1V forms complexes with two host hemolymph proteins, here named Pieris rapae hemolymph proteinase 8 (PrHP8) and P. rapae prophenoloxidase-activating proteinase 1 (PrPAP1), based on gene sequence blasting and phylogenetic analysis. The role of rPrPAP1 in the PPO activation cascade and its interaction with rPpS1V were confirmed. The stoichiometry of inhibition of PrPAP1 by PpS1V is 2.3. PpS1V also inhibits PPO activation in a non-natural host, Ostrinia furnacalis, through forming a complex with O. furnacalis serine protease 13 (OfSP13), an ortholog to PrPAP1. Our results identify a venom-enriched serpin isoform in P. puparum that inhibits host PPO activation, probably by forming a complex with host hemolymph proteinase PrPAP1.

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“…However, the PS1 toxins found in Lonomia caterpillar venoms possess fibrinolytic activity (3) (Figure 5), thereby constituting a case of convergent derivation with the reptilian peptidases. The venom of the parasitic wasp Cotesia rubecula contains a PS1-scaffold-derived protein (Vn50), which, similarly to the insect PS1 homologs from which it evolved, lacks a functional catalytic triad (His-Asp-Ser) because the serine residue is replaced by a glycine (13). The insect PS1 homologs from which Vn50 is derived are involved in a proteolytic cascade that causes hemolymph melanization, which is a primary defense reaction upon infection or invasion by parasites.…”

Section: Peptidase S1mentioning

confidence: 99%

The Toxicogenomic Multiverse: Convergent Recruitment of Proteins Into Animal Venoms

Fry

Roelants

Champagne

et al. 2009

Annu. Rev. Genom. Hum. Genet.

709

778

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Throughout evolution, numerous proteins have been convergently recruited into the venoms of various animals, including centipedes, cephalopods, cone snails, fish, insects (several independent venom systems), platypus, scorpions, shrews, spiders, toxicoferan reptiles (lizards and snakes), and sea anemones. The protein scaffolds utilized convergently have included AVIT/colipase/prokineticin, CAP, chitinase, cystatin, defensins, hyaluronidase, Kunitz, lectin, lipocalin, natriuretic peptide, peptidase S1, phospholipase A 2 , sphingomyelinase D, and SPRY. Many of these same venom protein types have also been convergently recruited for use in the hematophagous gland secretions of invertebrates (e.g., fleas, leeches, kissing bugs, mosquitoes, and ticks) and vertebrates (e.g., vampire bats). Here, we discuss a number of overarching structural, functional, and evolutionary generalities of the protein families from which these toxins have been frequently recruited and propose a revised and expanded working definition for venom. Given the large number of striking similarities between the protein compositions of conventional venoms and hematophagous secretions, we argue that the latter should also fall under the same definition. 483

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A serine proteinase homolog venom protein from an endoparasitoid wasp inhibits melanization of the host hemolymph

Cited by 147 publications

References 31 publications

An Ascovirus-Encoded RNase III Autoregulates Its Expression and Suppresses RNA Interference-Mediated Gene Silencing

An Ascovirus-Encoded RNase III Autoregulates Its Expression and Suppresses RNA Interference-Mediated Gene Silencing

A Venom Serpin Splicing Isoform of the Endoparasitoid Wasp Pteromalus puparum Suppresses Host Prophenoloxidase Cascade by Forming Complexes with Host Hemolymph Proteinases

The Toxicogenomic Multiverse: Convergent Recruitment of Proteins Into Animal Venoms

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