Growth-blocking peptide titer during larval development of parasitized and cold-stressed armyworm

Ohnishi, Atsushi; Hayakawa, Yoichi; Matsuda, Yusuke; Kwon, Kil‐Won; Takahashi, Tsuneo; Sekiguchi, Sadayoshi

doi:10.1016/0965-1748(95)00054-2

Cited by 39 publications

(19 citation statements)

References 17 publications

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“…GBPs purified from the plasma of parasitized and non-parasitized armyworm larvae consist of 25 AA and 23 AA residues, respectively [2,5]. The characterized cDNA encodes GBP consisting of 23 AA residues.…”

Section: The Gbp Mrna Sequencementioning

confidence: 99%

“…As we previously reported, after parasitization on Day 0 last larval instar, plasma GBP titer increased within one day [5]. During this period, it was interested to determine whether GBP mRNA levels correlate with plasma GBP peptide concentration.…”

Section: Northern Blot Analysesmentioning

confidence: 99%

“…From these results, it was proposed that GBP might be a hormone-like peptide which coordinates, along with JH, the regulation of larval characteristics in lepidopteran insects [3,4]. This hypothesis has recently been strengthened by quantifying GBP concentrations in the plasma during the late stages of larval development of the parasitized and non-parasitized host armyworm [5]. The highest level of plasma GBP titer detected on Day O of the penultimate instar gradually decreased throughout larval growth except for the temporary increase on Day O of the last larval instar.…”

Section: Introductionmentioning

confidence: 99%

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Molecular cloning and characterization of cDNA for insect biogenic peptide, growth‐blocking peptide

et al. 1995

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Growth-blocking peptide (GBP) is an insect biogenic peptide that prevents the onset of metamorphosis from larva to pupa. A cDNA coding for GBP is described. Mixed oligonucleotides derived from a GBP peptide sequence were used to generate amplified DNA by the polymerase chain reaction (PCR). Based on the sequence of the amplified DNA, a 41 bases oligonucleotide was designed for screening a cDNA library which was constructed from the armyworm Pseudaletia separata larvae parasitized with the parasitic wasp Cotesia kariyai. The cloned cDNA for GBP was 809 base pairs in length. An open reading frame of 429 base pairs encodes a pre-pro-peptide of 143 amino acid residues in which GBP is localized at the C-terminal region, and other three peptides including a putative signal peptide and appropriate processing sites for endoproteolytic cleavage precede the GBP sequence. Northern blot analyses demonstrate the presence of a 800-base mRNA transcript in fat body and 2.5-kilobase transcript in brain and nerve cord, suggesting the possibility that the transcription of GBP gene is regulated in a tissue-dependent manner. This interpretation was supported by isolating a GBP cDNA fragment from cDNA pool of brain-nerve cords. GBP mRNA is constantly expressed in both parasitized and non-parasitized last instar larvae and there is no difference in the levels of the mRNA between both larvae, thus indicating that parasitism may effect on translational or posttranslational level to elevate plasma GBP concentration.

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Section: The Gbp Mrna Sequencementioning

confidence: 99%

Section: Northern Blot Analysesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Molecular cloning and characterization of cDNA for insect biogenic peptide, growth‐blocking peptide

et al. 1995

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“…The fact that injection of 20 pmol of GBP into early last instar larvae of the armyworm retards larval growth and causes more than a few days delay in pupation clearly shows its growth blocking activity (2,3). We have since determined that GBP is a host gene product and that the change of titers of this peptide correlate well with the growth rate of insect larvae (4,5). Recently, injection studies of GBP indicated that low concentrations (lower than 1 pmol/larva) stimulated larval growth, whereas high concentrations (higher than 10 pmol/larva) retarded growth (6).…”

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confidence: 99%

Solution Structure of an Insect Growth Factor, Growth-blocking Peptide

Aizawa

Fujitani

Hayakawa

et al. 1999

Journal of Biological Chemistry

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Growth-blocking peptide (GBP) is an insect growth factor consisting of 25 amino acid residues that retards the development of lepidopteran larvae at high concentration while it stimulates larval growth at low concentration. In this study, we determined the solution structure of GBP by two-dimensional 1 H NMR spectroscopy. The structure contains a short segment of doublestranded ␤-sheet involving residues 11-13 and 19 -21 and a type-II ␤-turn in the loop region (residues 8 -11), whereas the N and C termini are disordered. This is the first report of the three-dimensional structure of the peptiderigic insect growth factor, and the structure of the well defined region of GBP was found to share similarity with that of the C-terminal domain of the epidermal growth factor (EGF). Because GBP has been reported to stimulate DNA synthesis of not only insect cells but also human keratinocyte cells at the same level with EGF, the structural similarity between GBP and EGF may lead to the interaction of GBP to EGF receptor.Endoparasitic wasps can alter the development of their hosts from larvae to pupae. This developmental disturbance allows the wasps to complete their larval growth and to emerge while the host is still in the larval stage, otherwise the wasp larvae would be trapped in the sclerotized pupal cuticles. Growthblocking peptide (GBP) 1 was originally isolated from the larval hemolymph of the host armyworm Pseudaletia separata whose development is halted in the last larval instar stage from parasitization by the parasitoid wasp Cotesia kariyai (1-3). The fact that injection of 20 pmol of GBP into early last instar larvae of the armyworm retards larval growth and causes more than a few days delay in pupation clearly shows its growth blocking activity (2, 3). We have since determined that GBP is a host gene product and that the change of titers of this peptide correlate well with the growth rate of insect larvae (4, 5). Recently, injection studies of GBP indicated that low concentrations (lower than 1 pmol/larva) stimulated larval growth, whereas high concentrations (higher than 10 pmol/larva) retarded growth (6). Furthermore, bioassay data revealed that several pmol/ml of GBP stimulated DNA synthesis of SF-9 insect cells and human keratinocyte cells, although several nmol/ml of GBP did not stimulate cell proliferation at all. Therefore, it is thought that GBP can act as a growth factor controlling the proliferation of a broad range of cells and the growth rate of whole larvae.To examine structural features of GBP, NMR was used in this study. The solution structure that we report here was obtained by two-dimensional 1 H NMR spectroscopy with the aid of distance geometry and simulated annealing. The threedimensional structure of GBP contains a short double-stranded ␤-sheet and a ␤-turn in the C-terminal region, while six residues in the N terminus and three residues in the C terminus are highly disordered. EXPERIMENTAL PROCEDURES 1H NMR Spectroscopy-The 25-residue peptide GBP was prepared by the Peptide Institute (Osa...

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“…After further washing twice with TC-100 containing 10% FBS (FBS-TC), the resulting plasmatocyte-enriched monolayer (approximately 80% pure, 9,000 cells/well) was used for the following experiments. The GBP (amino acid sequence: ENFSGGCVAGYMRTPDGRCKPTF) was synthesized by Fmoc method (Sigma) according to Ohnishi et al (1995), Strand et al (2000) and Aizawa et al (2001). The granulocyte monolayer was prepared according to Tojo et al (2000).…”

Section: Insectsmentioning

confidence: 99%

Effects of the virus-like particles of a braconid endoparasitoid, Meteorus pulchricornis, on hemocytes and hematopoietic organs of its noctuid host, Pseudaletia separata

Suzuki

Miura

Tanaka

2009

Appl. Entomol. Zool.

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Previously, we reported that virus-like particles of Meteorus pulchricornis (MpVLPs) induced apoptosis in hemocytes of its host, Pseudaletia separata, and that MpVLPs seem to especially damage the granulocyte population in vivo. The present study was conducted to elucidate more clearly the distinct behavior of two hemocyte populations in response to MpVLPs or parasitization. First, we examined the differences between plasmatocytes and granulocytes in their sensitivity to MpVLP-induced apoptosis and also in changes of their numbers after parasitization. MpVLPs induced apoptosis in both hemocyte species in vitro. The number of plasmatocytes increased slightly after parasitization in vivo unlike that of granulocytes. The BrdU incorporation assay indicated that the parasitization or the injection of venom containing MpVLPs (V(ϩ)VLP) enhanced the proliferation of plasmatocytes and suppressed that of granulocytes, accounting in part for the distinct responses shown by the respective hemocyte populations. Next, we examined the effects of V(ϩ)VLP on hematopoietic organs (HPOs), major tissues for hematopoiesis of P. separata. A large number (approximately 70-80%) of the cells released from cultured HPOs were determined to be plasmatocytes by the morphology and response to growth-blocking peptide. The injection of V(ϩ)VLP did not affect HPOs in terms of the hematopoietic activity and hemocyte species released. These results, together with our previous data, suggest that the plasmatocyte population was maintained by both supply from undamaged HPOs and the propagation of circulating cells during the initial phase of at least 24 h post-parasitization, while MpVLPs caused apoptosis irrespective of hemocyte species.

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Growth-blocking peptide titer during larval development of parasitized and cold-stressed armyworm

Cited by 39 publications

References 17 publications

Molecular cloning and characterization of cDNA for insect biogenic peptide, growth‐blocking peptide

Molecular cloning and characterization of cDNA for insect biogenic peptide, growth‐blocking peptide

Solution Structure of an Insect Growth Factor, Growth-blocking Peptide

Effects of the virus-like particles of a braconid endoparasitoid, Meteorus pulchricornis, on hemocytes and hematopoietic organs of its noctuid host, Pseudaletia separata

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