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Gerd Gade - One of the best experts on this subject based on the ideXlab platform.

  • analysis of peptide ligand specificity of different insect Adipokinetic Hormone receptors
    International Journal of Molecular Sciences, 2018
    Co-Authors: Elisabeth Marchal, Gerd Gade, Heather G Marco, Sam Schellens, Emilie Monjon, Evert Bruyninckx, Jozef Vanden Broeck, Heleen Verlinden
    Abstract:

    Adipokinetic Hormone (AKH) is a highly researched insect neuropeptide that induces the mobilization of carbohydrates and lipids from the fat body at times of high physical activity, such as flight and locomotion. As a naturally occurring ligand, AKH has undergone quite a number of amino acid changes throughout evolution, and in some insect species multiple AKHs are present. AKH acts by binding to a rhodopsin-like G protein-coupled receptor, which is related to the vertebrate gonadotropin-releasing Hormone receptors. In the current study, we have cloned AKH receptors (AKHRs) from seven different species, covering a wide phylogenetic range of insect orders: the fruit fly, Drosophila melanogaster, and the yellow fever mosquito, Aedes aegypti (Diptera); the red flour beetle, Tribolium castaneum, and the large pine weevil, Hylobius abietis (Coleoptera); the honeybee, Apis mellifera (Hymenoptera); the pea aphid, Acyrthosiphon pisum (Hemiptera); and the desert locust, Schistocerca gregaria (Orthoptera). The agonistic activity of different insect AKHs, including the respective endogenous AKHs, at these receptors was tested with a bioluminescence-based assay in Chinese hamster ovary cells. All receptors were activated by their endogenous ligand in the nanomolar range. Based on our data, we can refute the previously formulated hypothesis that a functional AKH signaling system is absent in the beneficial species, Apis mellifera. Furthermore, our data also suggest that some of the investigated AKH receptors, such as the mosquito AKHR, are more selective for the endogenous (conspecific) ligand, while others, such as the locust AKHR, are more promiscuous and can be activated by AKHs from many other insects. This information will be of high importance when further analyzing the potential use of AKHRs as targets for developing novel pest control agents.

  • Two novel tyrosine-containing peptides (Tyr^4) of the Adipokinetic Hormone family in beetles of the families Coccinellidae and Silphidae
    Amino Acids, 2015
    Co-Authors: Gerd Gade, Petr Simek, Heather G Marco
    Abstract:

    Novel members of the Adipokinetic Hormone family of peptides have been identified from the corpora cardiaca (CC) of two species of beetles representing two families, the Silphidae and the Coccinellidae. A crude CC extract (0.3 gland equivalents) of the burying beetle, Nicrophorus vespilloides , was active in mobilizing trehalose in a heterologous assay using the cockroach Periplaneta americana , whereas the CC extract (0.5 gland equivalents) of the ladybird beetle, Harmonia axyridis , exhibited no hypertrehalosemic activity. Primary sequences of one Adipokinetic Hormone from each species were elucidated by liquid chromatography coupled to electrospray mass spectrometry (LC–MS). The multiple MS^N electrospray mass data revealed an octapeptide with an unusual tyrosine residue at position 4 for each species: pGlu-Leu-Thr-Tyr-Ser-Thr-Gly-Trp amide for N. vespilloides (code-named Nicve-AKH) and pGlu-Ile-Asn-Tyr-Ser-Thr-Gly-Trp amide for H. axyridis (code-named Harax-AKH). Assignment of the correct sequences was confirmed by synthesis of the peptides and co-elution in reversed-phase high-performance liquid chromatography with fluorescence detection or by LC–MS. Moreover, synthetic peptides were shown to be active in the heterologous cockroach assay system, but Harax-AKH only at a dose of 30 pmol, which explains the negative result with the crude CC extract. It appears that the tyrosine residue at position 4 can be used as a diagnostic feature for certain beetle Adipokinetic peptides, because this feature has not been found in another order other than Coleoptera.

  • two novel tyrosine containing peptides tyr 4 of the Adipokinetic Hormone family in beetles of the families coccinellidae and silphidae
    Amino Acids, 2015
    Co-Authors: Gerd Gade, Petr Simek, Heather G Marco
    Abstract:

    Novel members of the Adipokinetic Hormone family of peptides have been identified from the corpora cardiaca (CC) of two species of beetles representing two families, the Silphidae and the Coccinellidae. A crude CC extract (0.3 gland equivalents) of the burying beetle, Nicrophorus vespilloides, was active in mobilizing trehalose in a heterologous assay using the cockroach Periplaneta americana, whereas the CC extract (0.5 gland equivalents) of the ladybird beetle, Harmonia axyridis, exhibited no hypertrehalosemic activity. Primary sequences of one Adipokinetic Hormone from each species were elucidated by liquid chromatography coupled to electrospray mass spectrometry (LC–MS). The multiple MSN electrospray mass data revealed an octapeptide with an unusual tyrosine residue at position 4 for each species: pGlu-Leu-Thr-Tyr-Ser-Thr-Gly-Trp amide for N. vespilloides (code-named Nicve-AKH) and pGlu-Ile-Asn-Tyr-Ser-Thr-Gly-Trp amide for H. axyridis (code-named Harax-AKH). Assignment of the correct sequences was confirmed by synthesis of the peptides and co-elution in reversed-phase high-performance liquid chromatography with fluorescence detection or by LC–MS. Moreover, synthetic peptides were shown to be active in the heterologous cockroach assay system, but Harax-AKH only at a dose of 30 pmol, which explains the negative result with the crude CC extract. It appears that the tyrosine residue at position 4 can be used as a diagnostic feature for certain beetle Adipokinetic peptides, because this feature has not been found in another order other than Coleoptera.

  • structure activity studies of drosophila Adipokinetic Hormone akh by a cellular expression system of dipteran akh receptors
    General and Comparative Endocrinology, 2012
    Co-Authors: Jelle Caers, Gerd Gade, Lise Peeters, Tom Janssen, Wouter De Haes, Liliane Schoofs
    Abstract:

    Structure–activity studies for the Adipokinetic Hormone receptor of insects were for the first time performed in a cellular expression system. A series of single amino acid replacement analogues for the endogenous Adipokinetic Hormone of Drosophila melanogaster (pGlu-Leu-Thr-Phe-Ser-Pro-Asp-Trp-NH2) were screened for activity with a bioluminescence cellular assay, expressing the G-protein coupled receptor. For this series of peptide analogues, one amino acid of the N-terminal tetrapeptide was successively replaced by alanine, while those of the C-terminal tetrapeptide were successively substituted by glycine; other modifications included the blocked N- and C-termini that were replaced by an acetylated alanine and a hydroxyl group, respectively. The analogue series was tested on the AKH receptors of two dipteran species, D. melanogaster and Anopheles gambiae. The blocked termini of the AKH peptide probably play a minor role in receptor interaction and activation, but are considered functionally important elements to protect the peptide against exopeptidases. In contrast, the amino acids at positions 2, 3, 4 and 5 from the N-terminus all seem to be crucial for receptor activation. This can be explained by the potential presence of a β-strand in this part of the peptide that interacts with the receptor. The inferred β-strand is probably followed by a β-turn in which the amino acids at positions 5–8 are involved. In this β-turn, the residues at positions 6 and 8 seem to be essential, as their substitutions induce only a very low degree of receptor activation. Replacement of Asp7, by contrast, does not influence receptor activation at all. This implies that its side chain is folded inside the β-turn so that no interaction with the receptor occurs.

  • the Adipokinetic Hormone family in chrysomeloidea structural and functional considerations
    ZooKeys, 2011
    Co-Authors: Gerd Gade, Heather G Marco
    Abstract:

    The presented work is a hybrid of an overview and an original research paper on peptides belonging to the Adipokinetic Hormone (AKH) family that are present in the corpora cardiaca of Chrysomeloidea. First, we introduce the AKH/red pigment-concentrating Hormone (RPCH) peptide family. Second, we collate the available primary sequence data on AKH peptides in Cerambycidae and Chrysomelidae, and we present new sequencing data (from previously unstudied species) obtained by liquid-chromatography coupled with ion trap electrospray ionisation mass spectrometry. Our expanded data set encompasses the primary structure of AKHs from seven species of Cerambycidae and three species of Chrysomelidae. All of these species synthesise the octapeptide code-named Peram-CAH-I (pGlu-Val-Asn-Phe-Ser-Pro-Asn-Trp amide). Whereas this is the sole AKH peptide in Cerambycidae, Chrysomelidae demonstrate a probable event of AKH gene duplication, thereby giving rise to an additional AKH. This second AKH peptide may be either Emppe-AKH (pGlu-Val-Asn-Phe-Thr-Pro-Asn-Trp amide) or Peram-CAH-II (pGlu-Leu-ThrPhe-Thr-Pro-Asn-Trp amide). The peptide distribution and structural data suggest that both families are closely related and that Peram-CAH-I is the ancestral peptide. We hypothesise on the molecular evolution of Emppe-AKH and Peram-CAH-II from the ancestral peptide due to nonsynonymous missense single nucleotide polymorphism in the nucleotide coding sequence of prepro-AKH. Finally, we review the biological significance of the AKH peptides as hyperprolinaemic Hormones in Chrysomeloidea, i.e. they cause an increase in the circulating concentration of proline. The mobilisation of proline has been demonstrated during flight in both cerambycid and chrysomelid beetles.

Ian Orchard - One of the best experts on this subject based on the ideXlab platform.

  • identification and characterization of the Adipokinetic Hormone corazonin related peptide signaling system in rhodnius prolixus
    FEBS Journal, 2015
    Co-Authors: Meet Zandawala, Zina Hamoudi, Amir Haddad, Ian Orchard
    Abstract:

    The mammalian gonadotropin-releasing Hormone is evolutionarily related to the arthropod Adipokinetic Hormone and the recently discovered Adipokinetic Hormone/corazonin-related peptide (ACP). The function of the ACP signaling system in arthropods is currently unknown. In the present study, we identify and characterize the ACP signaling system in the kissing bug Rhodnius prolixus. We isolated the complete cDNA sequence encoding R. prolixus ACP (Rhopr-ACP) and examined its expression pattern. Rhopr-ACP is predominantly expressed in the central nervous system. In particular, it is found in both the brain and corpus cardiacum (CC)/corpora allata (CA) complex. To gain an insight into its role in R. prolixus, we also isolated and functionally characterized cDNA sequences of three splice variants (Rhopr-ACPR-A, B and C) encoding R. prolixus ACP G protein-coupled receptor (Rhopr-ACPR). Rhopr-ACPR-A has only five transmembrane domains, whereas Rhopr-ACPR-B and C have all seven domains. Interestingly, Rhopr-ACPR-A, B and C were all activated by Rhopr-ACP, albeit at different sensitivities, when expressed in Chinese hamster ovary cells stably expressing the human G-protein G16 (CHO/G16). To our knowledge, this is the first study to isolate a truncated receptor cDNA in invertebrates that is functional in a heterologous expression system. Moreover, Rhopr-ACPR-B and C but not Rhopr-ACPR-A can be coupled with Gq α subunits. Expression profiling indicates that Rhopr-ACPR is highly expressed in the central nervous system, as well as the CC/CA complex, suggesting that it may control the release of other Hormones found in the CC in a manner analogous to gonadotropin-releasing Hormone. Temporal expression profiling shows that both Rhopr-ACP and Rhopr-ACPR are upregulated after ecdysis, suggesting that this neuropeptide may be involved in processes associated with post-ecdysis.

  • Identification and characterization of the Adipokinetic Hormone/corazonin‐related peptide signaling system in Rhodnius prolixus
    FEBS Journal, 2015
    Co-Authors: Meet Zandawala, Zina Hamoudi, Amir Haddad, Ian Orchard
    Abstract:

    The mammalian gonadotropin-releasing Hormone is evolutionarily related to the arthropod Adipokinetic Hormone and the recently discovered Adipokinetic Hormone/corazonin-related peptide (ACP). The function of the ACP signaling system in arthropods is currently unknown. In the present study, we identify and characterize the ACP signaling system in the kissing bug Rhodnius prolixus. We isolated the complete cDNA sequence encoding R. prolixus ACP (Rhopr-ACP) and examined its expression pattern. Rhopr-ACP is predominantly expressed in the central nervous system. In particular, it is found in both the brain and corpus cardiacum (CC)/corpora allata (CA) complex. To gain an insight into its role in R. prolixus, we also isolated and functionally characterized cDNA sequences of three splice variants (Rhopr-ACPR-A, B and C) encoding R. prolixus ACP G protein-coupled receptor (Rhopr-ACPR). Rhopr-ACPR-A has only five transmembrane domains, whereas Rhopr-ACPR-B and C have all seven domains. Interestingly, Rhopr-ACPR-A, B and C were all activated by Rhopr-ACP, albeit at different sensitivities, when expressed in Chinese hamster ovary cells stably expressing the human G-protein G16 (CHO/G16). To our knowledge, this is the first study to isolate a truncated receptor cDNA in invertebrates that is functional in a heterologous expression system. Moreover, Rhopr-ACPR-B and C but not Rhopr-ACPR-A can be coupled with Gq α subunits. Expression profiling indicates that Rhopr-ACPR is highly expressed in the central nervous system, as well as the CC/CA complex, suggesting that it may control the release of other Hormones found in the CC in a manner analogous to gonadotropin-releasing Hormone. Temporal expression profiling shows that both Rhopr-ACP and Rhopr-ACPR are upregulated after ecdysis, suggesting that this neuropeptide may be involved in processes associated with post-ecdysis.

  • Adipokinetic Hormone signalling system in the chagas disease vector rhodnius prolixus
    Insect Molecular Biology, 2015
    Co-Authors: Meet Zandawala, Angela B Lange, Zina Hamoudi, Ian Orchard
    Abstract:

    Neuropeptides and their G protein-coupled receptors are widespread throughout Metazoa and in several cases, clear orthologues can be identified in both protostomes and deuterostomes. One such neuropeptide is the insect Adipokinetic Hormone (AKH), which is related to the mammalian gonadotropinreleasing Hormone. AKH has been studied extensively and is known to mobilize lipid, carbohydrates and proline for energy-consuming activities such as flight. In order to determine the possible roles for this signalling system in Rhodnius prolixus, we isolated the cDNA sequences encoding R. prolixus AKH (Rhopr-AKH) and its receptor (Rhopr-AKHR). We also examined their spatial expression pattern using quantitative PCR. Our expression analysis indicates that Rhopr-AKH is only expressed in the corpus cardiacum of fifth-instars and adults. Rhopr-AKHR ,b y contrast, is expressed in several peripheral tissues including the fat body. The expression of the receptor in the fat body suggests that AKH is involved in lipid mobilization, which was confirmed by knockdown of Rhopr-AKHR via RNA interference. Adult males that had been injected with double-stranded RNA (dsRNA) for Rhopr-AKHR exhibited increased lipid content in the fat body and decreased lipid levels in the haemolymph. Moreover, injection of Rhopr-AKH in Rhopr-AKHR dsRNA-treated males failed to elevate haemolymph lipid levels, confirming that this is indeed the receptor for Rhopr-AKH.

  • reprint of the distribution and physiological effects of three evolutionarily and sequence related neuropeptides in rhodnius prolixus Adipokinetic Hormone corazonin and Adipokinetic Hormone corazonin related peptide
    General and Comparative Endocrinology, 2014
    Co-Authors: H. Patel, Jan A Veenstra, Ian Orchard, Angela B Lange
    Abstract:

    We have examined the distribution and physiological effects of three evolutionarily and sequence-related neuropeptides in Rhodnius prolixus. These neuropeptides, Adipokinetic Hormone (RhoprAKH), corazonin (CRZ) and Adipokinetic Hormone/corazonin-related peptide (RhoprACP) are present in distinct, non-overlapping neuronal subsets in the central nervous system (CNS), as determined by immunohistochemistry. Corazonin-like immunoreactive cell bodies are present in the brain and ventral nerve cord, whereas ACP-like immunoreactive cell bodies are only present in the brain, and AKH-like immunoreactive cell bodies only present in the corpus cardiacum (CC). The immunoreactivity to ACP, CRZ and AKH in R. prolixus suggests that ACP and CRZ are released within the CNS, and that CRZ and AKH are released as neuroHormones from the CC. Injection of RhoprAKH into adult males elevated haemolymph lipid levels, but injection of CRZ or RhoprACP failed to have any effect on haemolymph lipid levels. Corazonin stimulated an increase in heart-beat frequency in vitro, but RhoprAKH and RhoprACP failed to do so. Thus, although all three neuropeptides share sequence similarity, the AKH and CRZ receptors only respond to their own ligand.

  • The distribution and physiological effects of three evolutionarily and sequence-related neuropeptides in Rhodnius prolixus: Adipokinetic Hormone, corazonin and Adipokinetic Hormone/corazonin-related peptide.
    General and comparative endocrinology, 2013
    Co-Authors: H. Patel, Jan A Veenstra, Ian Orchard, Angela B Lange
    Abstract:

    We have examined the distribution and physiological effects of three evolutionarily and sequence-related neuropeptides in Rhodnius prolixus. These neuropeptides, Adipokinetic Hormone (RhoprAKH), corazonin (CRZ) and Adipokinetic Hormone/corazonin-related peptide (RhoprACP) are present in distinct, non-overlapping neuronal subsets in the central nervous system (CNS), as determined by immunohistochemistry. Corazonin-like immunoreactive cell bodies are present in the brain and ventral nerve cord, whereas ACP-like immunoreactive cell bodies are only present in the brain, and AKH-like immunoreactive cell bodies only present in the corpus cardiacum (CC). The immunoreactivity to ACP, CRZ and AKH in R. prolixus suggests that ACP and CRZ are released within the CNS, and that CRZ and AKH are released as neuroHormones from the CC. Injection of RhoprAKH into adult males elevated haemolymph lipid levels, but injection of CRZ or RhoprACP failed to have any effect on haemolymph lipid levels. Corazonin stimulated an increase in heart-beat frequency in vitro, but RhoprAKH and RhoprACP failed to do so. Thus, although all three neuropeptides share sequence similarity, the AKH and CRZ receptors only respond to their own ligand.

Heather G Marco - One of the best experts on this subject based on the ideXlab platform.

  • analysis of peptide ligand specificity of different insect Adipokinetic Hormone receptors
    International Journal of Molecular Sciences, 2018
    Co-Authors: Elisabeth Marchal, Gerd Gade, Heather G Marco, Sam Schellens, Emilie Monjon, Evert Bruyninckx, Jozef Vanden Broeck, Heleen Verlinden
    Abstract:

    Adipokinetic Hormone (AKH) is a highly researched insect neuropeptide that induces the mobilization of carbohydrates and lipids from the fat body at times of high physical activity, such as flight and locomotion. As a naturally occurring ligand, AKH has undergone quite a number of amino acid changes throughout evolution, and in some insect species multiple AKHs are present. AKH acts by binding to a rhodopsin-like G protein-coupled receptor, which is related to the vertebrate gonadotropin-releasing Hormone receptors. In the current study, we have cloned AKH receptors (AKHRs) from seven different species, covering a wide phylogenetic range of insect orders: the fruit fly, Drosophila melanogaster, and the yellow fever mosquito, Aedes aegypti (Diptera); the red flour beetle, Tribolium castaneum, and the large pine weevil, Hylobius abietis (Coleoptera); the honeybee, Apis mellifera (Hymenoptera); the pea aphid, Acyrthosiphon pisum (Hemiptera); and the desert locust, Schistocerca gregaria (Orthoptera). The agonistic activity of different insect AKHs, including the respective endogenous AKHs, at these receptors was tested with a bioluminescence-based assay in Chinese hamster ovary cells. All receptors were activated by their endogenous ligand in the nanomolar range. Based on our data, we can refute the previously formulated hypothesis that a functional AKH signaling system is absent in the beneficial species, Apis mellifera. Furthermore, our data also suggest that some of the investigated AKH receptors, such as the mosquito AKHR, are more selective for the endogenous (conspecific) ligand, while others, such as the locust AKHR, are more promiscuous and can be activated by AKHs from many other insects. This information will be of high importance when further analyzing the potential use of AKHRs as targets for developing novel pest control agents.

  • Two novel tyrosine-containing peptides (Tyr^4) of the Adipokinetic Hormone family in beetles of the families Coccinellidae and Silphidae
    Amino Acids, 2015
    Co-Authors: Gerd Gade, Petr Simek, Heather G Marco
    Abstract:

    Novel members of the Adipokinetic Hormone family of peptides have been identified from the corpora cardiaca (CC) of two species of beetles representing two families, the Silphidae and the Coccinellidae. A crude CC extract (0.3 gland equivalents) of the burying beetle, Nicrophorus vespilloides , was active in mobilizing trehalose in a heterologous assay using the cockroach Periplaneta americana , whereas the CC extract (0.5 gland equivalents) of the ladybird beetle, Harmonia axyridis , exhibited no hypertrehalosemic activity. Primary sequences of one Adipokinetic Hormone from each species were elucidated by liquid chromatography coupled to electrospray mass spectrometry (LC–MS). The multiple MS^N electrospray mass data revealed an octapeptide with an unusual tyrosine residue at position 4 for each species: pGlu-Leu-Thr-Tyr-Ser-Thr-Gly-Trp amide for N. vespilloides (code-named Nicve-AKH) and pGlu-Ile-Asn-Tyr-Ser-Thr-Gly-Trp amide for H. axyridis (code-named Harax-AKH). Assignment of the correct sequences was confirmed by synthesis of the peptides and co-elution in reversed-phase high-performance liquid chromatography with fluorescence detection or by LC–MS. Moreover, synthetic peptides were shown to be active in the heterologous cockroach assay system, but Harax-AKH only at a dose of 30 pmol, which explains the negative result with the crude CC extract. It appears that the tyrosine residue at position 4 can be used as a diagnostic feature for certain beetle Adipokinetic peptides, because this feature has not been found in another order other than Coleoptera.

  • two novel tyrosine containing peptides tyr 4 of the Adipokinetic Hormone family in beetles of the families coccinellidae and silphidae
    Amino Acids, 2015
    Co-Authors: Gerd Gade, Petr Simek, Heather G Marco
    Abstract:

    Novel members of the Adipokinetic Hormone family of peptides have been identified from the corpora cardiaca (CC) of two species of beetles representing two families, the Silphidae and the Coccinellidae. A crude CC extract (0.3 gland equivalents) of the burying beetle, Nicrophorus vespilloides, was active in mobilizing trehalose in a heterologous assay using the cockroach Periplaneta americana, whereas the CC extract (0.5 gland equivalents) of the ladybird beetle, Harmonia axyridis, exhibited no hypertrehalosemic activity. Primary sequences of one Adipokinetic Hormone from each species were elucidated by liquid chromatography coupled to electrospray mass spectrometry (LC–MS). The multiple MSN electrospray mass data revealed an octapeptide with an unusual tyrosine residue at position 4 for each species: pGlu-Leu-Thr-Tyr-Ser-Thr-Gly-Trp amide for N. vespilloides (code-named Nicve-AKH) and pGlu-Ile-Asn-Tyr-Ser-Thr-Gly-Trp amide for H. axyridis (code-named Harax-AKH). Assignment of the correct sequences was confirmed by synthesis of the peptides and co-elution in reversed-phase high-performance liquid chromatography with fluorescence detection or by LC–MS. Moreover, synthetic peptides were shown to be active in the heterologous cockroach assay system, but Harax-AKH only at a dose of 30 pmol, which explains the negative result with the crude CC extract. It appears that the tyrosine residue at position 4 can be used as a diagnostic feature for certain beetle Adipokinetic peptides, because this feature has not been found in another order other than Coleoptera.

  • the Adipokinetic Hormone family in chrysomeloidea structural and functional considerations
    ZooKeys, 2011
    Co-Authors: Gerd Gade, Heather G Marco
    Abstract:

    The presented work is a hybrid of an overview and an original research paper on peptides belonging to the Adipokinetic Hormone (AKH) family that are present in the corpora cardiaca of Chrysomeloidea. First, we introduce the AKH/red pigment-concentrating Hormone (RPCH) peptide family. Second, we collate the available primary sequence data on AKH peptides in Cerambycidae and Chrysomelidae, and we present new sequencing data (from previously unstudied species) obtained by liquid-chromatography coupled with ion trap electrospray ionisation mass spectrometry. Our expanded data set encompasses the primary structure of AKHs from seven species of Cerambycidae and three species of Chrysomelidae. All of these species synthesise the octapeptide code-named Peram-CAH-I (pGlu-Val-Asn-Phe-Ser-Pro-Asn-Trp amide). Whereas this is the sole AKH peptide in Cerambycidae, Chrysomelidae demonstrate a probable event of AKH gene duplication, thereby giving rise to an additional AKH. This second AKH peptide may be either Emppe-AKH (pGlu-Val-Asn-Phe-Thr-Pro-Asn-Trp amide) or Peram-CAH-II (pGlu-Leu-ThrPhe-Thr-Pro-Asn-Trp amide). The peptide distribution and structural data suggest that both families are closely related and that Peram-CAH-I is the ancestral peptide. We hypothesise on the molecular evolution of Emppe-AKH and Peram-CAH-II from the ancestral peptide due to nonsynonymous missense single nucleotide polymorphism in the nucleotide coding sequence of prepro-AKH. Finally, we review the biological significance of the AKH peptides as hyperprolinaemic Hormones in Chrysomeloidea, i.e. they cause an increase in the circulating concentration of proline. The mobilisation of proline has been demonstrated during flight in both cerambycid and chrysomelid beetles.

  • the first identified neuropeptide in the insect order megaloptera a novel member of the Adipokinetic Hormone family in the alderfly sialis lutaria
    Peptides, 2009
    Co-Authors: Gerd Gade, Petr Simek, Heather G Marco
    Abstract:

    Abstract This is the first report on the structural identity of a neuropeptide of the insect order Megaloptera. A peptide was isolated and sequenced from the retrocerebral corpora cardiaca glands of the alderfly, Sialis lutaria. The sequence of the peptide was deduced from the multiple MSN electrospray mass data as that of an octapeptide: pGlu-Ile/Leu-Thr-Phe-Thr-Pro-Ser-Trp amide. The ambiguity about the amino acid at position 2, Leu or Ile, was solved by comparing retention time on reversed-phase HPLC and establishing co-elution with the synthetic Leu2-form which also had exactly the same MS2 mass spectra as the natural peptide. The sequence represents a novel peptide of the Adipokinetic Hormone family which has already more than 40 members. Interestingly, the primary structure is identical to that predicted from genome information for the Adipokinetic Hormone of the yellow fever mosquito, Aedes aegypti. Since alderflies are not known for their active flight metabolism but produce a rather high number of eggs, it is anticipated that the alderfly is a good study object to establish a possible role of the novel peptide to regulate fat mobilization from the fat body and transport into the egg, thereby playing a role in the control of reproductive processes.

Angela B Lange - One of the best experts on this subject based on the ideXlab platform.

  • Adipokinetic Hormone signalling system in the chagas disease vector rhodnius prolixus
    Insect Molecular Biology, 2015
    Co-Authors: Meet Zandawala, Angela B Lange, Zina Hamoudi, Ian Orchard
    Abstract:

    Neuropeptides and their G protein-coupled receptors are widespread throughout Metazoa and in several cases, clear orthologues can be identified in both protostomes and deuterostomes. One such neuropeptide is the insect Adipokinetic Hormone (AKH), which is related to the mammalian gonadotropinreleasing Hormone. AKH has been studied extensively and is known to mobilize lipid, carbohydrates and proline for energy-consuming activities such as flight. In order to determine the possible roles for this signalling system in Rhodnius prolixus, we isolated the cDNA sequences encoding R. prolixus AKH (Rhopr-AKH) and its receptor (Rhopr-AKHR). We also examined their spatial expression pattern using quantitative PCR. Our expression analysis indicates that Rhopr-AKH is only expressed in the corpus cardiacum of fifth-instars and adults. Rhopr-AKHR ,b y contrast, is expressed in several peripheral tissues including the fat body. The expression of the receptor in the fat body suggests that AKH is involved in lipid mobilization, which was confirmed by knockdown of Rhopr-AKHR via RNA interference. Adult males that had been injected with double-stranded RNA (dsRNA) for Rhopr-AKHR exhibited increased lipid content in the fat body and decreased lipid levels in the haemolymph. Moreover, injection of Rhopr-AKH in Rhopr-AKHR dsRNA-treated males failed to elevate haemolymph lipid levels, confirming that this is indeed the receptor for Rhopr-AKH.

  • reprint of the distribution and physiological effects of three evolutionarily and sequence related neuropeptides in rhodnius prolixus Adipokinetic Hormone corazonin and Adipokinetic Hormone corazonin related peptide
    General and Comparative Endocrinology, 2014
    Co-Authors: H. Patel, Jan A Veenstra, Ian Orchard, Angela B Lange
    Abstract:

    We have examined the distribution and physiological effects of three evolutionarily and sequence-related neuropeptides in Rhodnius prolixus. These neuropeptides, Adipokinetic Hormone (RhoprAKH), corazonin (CRZ) and Adipokinetic Hormone/corazonin-related peptide (RhoprACP) are present in distinct, non-overlapping neuronal subsets in the central nervous system (CNS), as determined by immunohistochemistry. Corazonin-like immunoreactive cell bodies are present in the brain and ventral nerve cord, whereas ACP-like immunoreactive cell bodies are only present in the brain, and AKH-like immunoreactive cell bodies only present in the corpus cardiacum (CC). The immunoreactivity to ACP, CRZ and AKH in R. prolixus suggests that ACP and CRZ are released within the CNS, and that CRZ and AKH are released as neuroHormones from the CC. Injection of RhoprAKH into adult males elevated haemolymph lipid levels, but injection of CRZ or RhoprACP failed to have any effect on haemolymph lipid levels. Corazonin stimulated an increase in heart-beat frequency in vitro, but RhoprAKH and RhoprACP failed to do so. Thus, although all three neuropeptides share sequence similarity, the AKH and CRZ receptors only respond to their own ligand.

  • The distribution and physiological effects of three evolutionarily and sequence-related neuropeptides in Rhodnius prolixus: Adipokinetic Hormone, corazonin and Adipokinetic Hormone/corazonin-related peptide.
    General and comparative endocrinology, 2013
    Co-Authors: H. Patel, Jan A Veenstra, Ian Orchard, Angela B Lange
    Abstract:

    We have examined the distribution and physiological effects of three evolutionarily and sequence-related neuropeptides in Rhodnius prolixus. These neuropeptides, Adipokinetic Hormone (RhoprAKH), corazonin (CRZ) and Adipokinetic Hormone/corazonin-related peptide (RhoprACP) are present in distinct, non-overlapping neuronal subsets in the central nervous system (CNS), as determined by immunohistochemistry. Corazonin-like immunoreactive cell bodies are present in the brain and ventral nerve cord, whereas ACP-like immunoreactive cell bodies are only present in the brain, and AKH-like immunoreactive cell bodies only present in the corpus cardiacum (CC). The immunoreactivity to ACP, CRZ and AKH in R. prolixus suggests that ACP and CRZ are released within the CNS, and that CRZ and AKH are released as neuroHormones from the CC. Injection of RhoprAKH into adult males elevated haemolymph lipid levels, but injection of CRZ or RhoprACP failed to have any effect on haemolymph lipid levels. Corazonin stimulated an increase in heart-beat frequency in vitro, but RhoprAKH and RhoprACP failed to do so. Thus, although all three neuropeptides share sequence similarity, the AKH and CRZ receptors only respond to their own ligand.

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  • structure activity studies of drosophila Adipokinetic Hormone akh by a cellular expression system of dipteran akh receptors
    General and Comparative Endocrinology, 2012
    Co-Authors: Jelle Caers, Gerd Gade, Lise Peeters, Tom Janssen, Wouter De Haes, Liliane Schoofs
    Abstract:

    Structure–activity studies for the Adipokinetic Hormone receptor of insects were for the first time performed in a cellular expression system. A series of single amino acid replacement analogues for the endogenous Adipokinetic Hormone of Drosophila melanogaster (pGlu-Leu-Thr-Phe-Ser-Pro-Asp-Trp-NH2) were screened for activity with a bioluminescence cellular assay, expressing the G-protein coupled receptor. For this series of peptide analogues, one amino acid of the N-terminal tetrapeptide was successively replaced by alanine, while those of the C-terminal tetrapeptide were successively substituted by glycine; other modifications included the blocked N- and C-termini that were replaced by an acetylated alanine and a hydroxyl group, respectively. The analogue series was tested on the AKH receptors of two dipteran species, D. melanogaster and Anopheles gambiae. The blocked termini of the AKH peptide probably play a minor role in receptor interaction and activation, but are considered functionally important elements to protect the peptide against exopeptidases. In contrast, the amino acids at positions 2, 3, 4 and 5 from the N-terminus all seem to be crucial for receptor activation. This can be explained by the potential presence of a β-strand in this part of the peptide that interacts with the receptor. The inferred β-strand is probably followed by a β-turn in which the amino acids at positions 5–8 are involved. In this β-turn, the residues at positions 6 and 8 seem to be essential, as their substitutions induce only a very low degree of receptor activation. Replacement of Asp7, by contrast, does not influence receptor activation at all. This implies that its side chain is folded inside the β-turn so that no interaction with the receptor occurs.

  • aprp the second peptide encoded by the Adipokinetic Hormone gene s is highly conserved in evolution a role in control of ecdysteroidogenesis
    Annals of the New York Academy of Sciences, 2009
    Co-Authors: Arnold De Loof, Tim Vandersmissen, Jurgen Huybrechts, Bart Landuyt, Geert Baggerman, Elke Clynen, Marleen Lindemans, Steven J Husson, Liliane Schoofs
    Abstract:

    Since the early days of cloning the first Adipokinetic Hormone (AKH) gene, researchers recognized that this gene also codes for a joining region and for a second peptide called Adipokinetic Hormone precursor related peptide (APRP). In species with more than one AKH gene, such as locusts, APRPs can form both homodimers and heterodimers. Database analysis showed that APRPs might belong to the ancient family of growth Hormone releasing factor but they still are functionally orphan. We investigated whether some of the APRP forms play a role in control of reproduction or/and growth via stimulation of ecdysteroidogenesis.

  • new insights in Adipokinetic Hormone akh precursor processing in locusta migratoria obtained by capillary liquid chromatography tandem mass spectrometry
    Peptides, 2002
    Co-Authors: Geert Baggerman, D. J. Van Der Horst, Jurgen Huybrechts, Elke Clynen, Korneel Hens, Lucien F Harthoorn, Constantine Poulos, A De Loof, Liliane Schoofs
    Abstract:

    After translation, the AKH I and AKH II precursors form three dimeric constructs prior to further processing into the respective AKHs and three dimeric Adipokinetic Hormone Precursor Related Peptides or APRPs (two homodimers and one heterodimer). By capillary liquid chromatography-tandem mass spectrometry we demonstrate that the APRPs in Locusta migratoria are further processed to form two smaller neuropeptides: DAADFADPYSFL (residue 36 to 47 of the AKH I precursor) and YADPNADPMAFL (residue 34 to 45 of the AKH II precursor). The peptides are designated as Adipokinetic Hormone Joining Peptide 1 (AKH-JP I) and 2 (AKH-JP II) respectively. Within the AKH I and AKH II precursor molecules, the classic KK and RR processing sites separate the AKH-JPs from the AKH I and II respectively. At the carboxyterminus, both AKH-JP I and II are flanked by Tyr-Arg, a cleaving site not described before. Such an unusual cleavage site suggests the presence, in the corpora cardiaca, of specific convertases. The AKH-JP-II does not stimulate lipid release from the fat body nor does it stimulate glycogen phosphorylase activity, both key functions of AKH. © 2002 Elsevier Science Inc. All rights reserved.

  • isolation and characterization of an Adipokinetic Hormone release inducing factor in locusts the crustacean cardioactive peptide
    Endocrinology, 1997
    Co-Authors: Dirk Veelaert, Liliane Schoofs, H G B Vullings, J H B Diederen, P Passier, Bart Devreese, J Vanden Broeck, J Van Beeumen, A De Loof
    Abstract:

    A methanolic extract of 7000 desert locust (Schistocerca gregaria) brains contains several factors that stimulate the in vitro release of Adipokinetic Hormone (AKH) by glandular cells of locust (Locusta migratoria and Schistocerca gregaria) corpora cardiaca. The most potent one has now been fully identified. Matrix-assisted laser desorption ionization mass spectrometry-time of flight analysis revealed a mass of 954.6 Da. The primary structure of the peptide, Pro-Phe-Cys-Asn-Ala-Phe-Thr-Gly-Cys-NH2, appeared identical to that of a previously identified crustacean cardioactive peptide. This myotropin was first isolated from the shore crab, Carcinus maenas, and later from several insect species, but was never reported in the context of AKH release. The present study shows that synthetic crustacean cardioactive peptide induces the release of AKH from corpora cardiaca in a dose-dependent manner when tested in concentrations ranging from 10−5-10−9 m. This is the first demonstration in invertebrates of a peptide...