TY - JOUR A1 - Blenau, Wolfgang A1 - Baumann, Arnd T1 - Molecular and pharmacological properties of insect biogenic amine receptors : lessons from Drosophila melanogaster and Apis mellifera Y1 - 2001 SN - 0739-4462 ER - TY - GEN A1 - Blenau, Wolfgang A1 - Scheiner, Ricarda A1 - Plückhahn, Stephanie A1 - Oney, Bahar A1 - Erber, Joachim T1 - Behavioural pharmacology of octopamine, tyramine and dopamine in honey bees N2 - In the honey bee, responsiveness to sucrose correlates with many behavioural parameters such as age of first foraging, foraging role and learning. Sucrose responsiveness can be measured using the proboscis extension response (PER) by applying sucrose solutions of increasing concentrations to the antenna of a bee. We tested whether the biogenic amines octopamine, tyramine and dopamine, and the dopamine receptor agonist 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene (6,7-ADTN) can modulate sucrose responsiveness. The compounds were either injected into the thorax or fed in sucrose solution to compare different methods of application. Injection and feeding of tyramine or octopamine significantly increased sucrose responsiveness. Dopamine decreased sucrose responsiveness when injected into the thorax. Feeding of dopamine had no effect. Injection of 6,7-ADTN into the thorax and feeding of 6,7-ADTN reduced sucrose responsiveness significantly. These data demonstrate that sucrose responsiveness in honey bees can be modulated by biogenic amines, which has far reaching consequences for other types of behaviour in this insect. (C) 2002 Elsevier Science B.V. All rights reserved. KW - Honey bee KW - insect KW - proboscis extension response KW - sucrose responsiveness KW - biogenic amines Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44308 ER - TY - GEN A1 - Blenau, Wolfgang A1 - Grohmann, Lore A1 - Erber, Joachim A1 - Ebert, Paul R. A1 - Strünker, Timo A1 - Baumann, Arnd T1 - Molecular and functional characterization of an octopamine receptor from honeybee (Apis mellifera) brain N2 - Biogenic amines and their receptors regulate and modulate many physiological and behavioural processes in animals. In vertebrates, octopamine is only found in trace amounts and its function as a true neurotransmitter is unclear. In protostomes, however, octopamine can act as neurotransmitter, neuromodulator and neurohormone. In the honeybee, octopamine acts as a neuromodulator and is involved in learning and memory formation. The identification of potential octopamine receptors is decisive for an understanding of the cellular pathways involved in mediating the effects of octopamine. Here we report the cloning and functional characterization of the first octopamine receptor from the honeybee, Apis mellifera . The gene was isolated from a brain-specific cDNA library. It encodes a protein most closely related to octopamine receptors from Drosophila melanogaster and Lymnea stagnalis . Signalling properties of the cloned receptor were studied in transiently transfected human embryonic kidney (HEK) 293 cells. Nanomolar to micromolar concentrations of octopamine induced oscillatory increases in the intracellular Ca2+ concentration. In contrast to octopamine, tyramine only elicited Ca2+ responses at micromolar concentrations. The gene is abundantly expressed in many somata of the honeybee brain, suggesting that this octopamine receptor is involved in the processing of sensory inputs, antennal motor outputs and higher-order brain functions. KW - Biogenic amine KW - Ca2+ KW - cyclic AMP KW - G protein-coupled receptor KW - insect Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44293 ER - TY - GEN A1 - Blenau, Wolfgang A1 - Baumann, Arnd T1 - Aminergic signal transduction in invertebrates : focus on tyramine and octopamine receptors N2 - Electro-chemical signal transduction is the basis of communication between n eurons and their target cells. An important group of neuroactive substances that are released by action potentials from neurons are the biogenic amines. These a re small organic molecules that bind to specific receptors located in the target cell membrane. Once activated these receptors cause changes in the intracellula r concentration of second messengers, i.e. cyclic nucleotides, phosphoinositides , or Ca2+, leading to slow but long-lasting cellular responses. Biochemical, pha rmacological, physiological, and molecular biological approaches have unequivoca lly shown that biogenic amines are important regulators of cellular function in both vertebrates and invertebrates. In this review, we will concentrate on the p roperties of two biogenic amines and their receptors that were originally identi fied in invertebrates: tyramine and octopamine.  T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 107 Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44271 ER - TY - GEN A1 - Blenau, Wolfgang A1 - Mustard, Julie A. A1 - Hamilton, Ingrid S. A1 - Ward, Vernon K. A1 - Ebert, Paul R. A1 - Mercer, Alison R. T1 - Analysis of two D1-like dopamine receptors from the honey bee Apis mellifera reveals agonist-independent activity N2 - Dopamine is found in many invertebrate organisms, including insects, however, the mechanisms through which this amine operates remain unclear. We have expressed two dopamine receptors cloned from honey bee (AmDOP1 and AmDOP2) in insect cells (Spodoptera frugiperda), and compared their pharmacology directly using production of cAMP as a functional assay. In each assay, AmDOP1 receptors required lower concentrations of dopamine and 6,7-ADTN for maximal activation than AmDOP2 receptors. Conversely, butaclamol and cis(Z)-flupentixol were more potent at blocking the cAMP response mediated through AmDOP2 than AmDOP1 receptors. Expression of AmDOP1, but not AmDOP2, receptors significantly increased levels of cAMP even in the absence of ligand. This constitutive activity was blocked by cis(Z)-flupentixol. This work provides the first evidence of a constitutively activated dopamine receptor in invertebrates and suggests that although AmDOP1 and AmDOP2 share much less homology than their vertebrate counterparts, they display a number of functional parallels with the mammalian D1-like dopamine receptors. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 109 KW - G protein-coupled receptor KW - Biogenic amine KW - Invertebrate KW - cAMP KW - Baculovirus Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44378 ER - TY - JOUR A1 - Marg, S. A1 - Walz, Bernd A1 - Blenau, Wolfgang T1 - The effects of dopamine receptor agonists and antagonists on the secretory rate of cockroach (Periplaneta americana) salivary glands N2 - The acinar salivary glands of the cockroach, Periplaneta americana, are innervated by dopaminergic and serotonergic nerve fibers. Serotonin stimulates the secretion of protein-rich saliva, whereas dopamine causes the production of protein-free saliva. This suggests that dopamine acts selectively on ion-transporting peripheral cells within the acini and the duct cells, and that serotonin acts on the protein-producing central cells of the acini. We have investigated the pharmacology of the dopamine-induced secretory activity of the salivary gland of Periplaneta americana by testing several dopamine receptor agonists and antagonists. The effects of dopamine can be mimicked by the non-selective dopamine receptor agonist 6,7-ADTN and, less effectively, by the vertebrate D1 receptor-selective agonist chloro-APB. The vertebrate D1 receptor-selective agonist SKF 38393 and vertebrate D2 receptor-selective agonist R(-)- TNPA were ineffective. R(+)-Lisuride induces a secretory response with a slower onset and a lower maximal response compared with dopamine-induced secretion. However, lisuride-stimulated glands continue secreting saliva, even after lisuride-washout. Dopamine-induced secretions can be blocked by the vertebrate dopamine receptor antagonists cis(Z)- flupenthixol, chlorpromazine, and S(+)-butaclamol. Our pharmacological data do not unequivocally indicate whether the dopamine receptors on the Periplaneta salivary glands belong to the D1 or D2 subfamily of dopamine receptors, but we can confirm that the pharmacology of invertebrate dopamine receptors is remarkably different from that of their vertebrate counterparts. (C) 2004 Elsevier Ltd. All rights reserved Y1 - 2004 SN - 0022-1910 ER - TY - JOUR A1 - Blenau, Wolfgang A1 - Baumann, Arnd T1 - Molecular characterization of the ebony gene from the American cockroach, Periplaneta americana N2 - Biogenic amines are an important class of primary messengers in the central (CNS) and peripheral nervous systems and in peripheral organs. These substances regulate and modulate many physiological and behavioral processes. Various inactivation mechanisms for these substances exist to terminate biogenic amine-mediated signal transduction. In vertebrates, the enzymes monoamine oxidase and/or catechol-O-methyl-transferase are involved in these processes. In insects, however, in which both enzymes are low in abundance or absent, biogenic amines are inactivated mainly by N- acetylation or O-sulphation. In Droso-philo, beta-alanyl conjugation mediated by the Ebony protein has recently been shown to be a novel and alternative pathway for biogenic amine inactivation. Here, we report the cloning of ebony cDNA (Peaebony) from a brain-specific cDNA library of the cockroach Periplaneta americana. The open reading frame encodes a protein of 860 amino acid residues (PeaEbony). The PeaEbony polypeptide shares homology to Ebony sequences from Anopheles gambiae, Apis mellifera, and Drosophila melonogaster. In addition, PeaEbony exhibits sequence similarity to a family of microbial non-ribosomal peptide synthetases. The mRNA encoding PeaEbony is highly expressed in the cockroach brain and to a lesser extent in the salivary glands. PeaEbony is, therefore, probably involved in the inactivation of various biogenic amines through beta-alanyl conjugation in the cockroach CNS. Since the salivary glands in Periplaneta are innervated by dopaminergic and serotonergic neurons, PeaEbony probably also biochemically modifies dopamine and serotonin in these acinar glands. Arch. Insect Biochem. (c) 2005 Wiley-Liss, Inc Y1 - 2005 ER - TY - JOUR A1 - Bogen, Oliver A1 - Bender, Olaf A1 - Schlenstedt, Jana A1 - Goswami, C. A1 - Schroder, W. A1 - Blenau, Wolfgang A1 - Gillen, C. A1 - Dreger, M. A1 - Hucho, F. T1 - Neuronal expression of the IB4-binding versican Y1 - 2005 SN - 0022-3042 ER - TY - JOUR A1 - Rietdorf, Katja A1 - Blenau, Wolfgang A1 - Walz, Bernd T1 - Protein secretion in cockroach salivary glands requires an increase in intracellular cAMP and Ca2+ concentrations N2 - The salivary glands in the cockroach Periplaneta americana secrete protein-containing saliva when stimulated by serotonin (5-HT) and protein-free saliva upon dopamine stimulation. In order to obtain information concerning the signalling pathways involved in 5-HT-induced protein secretion, we have determined the protein content of saliva secreted after experimental manipulations that potentially elevate intracellular Ca2+ and cyclic nucleotide concentrations in isolated glands. We have found that 5-HT stimulates the rate of protein secretion in a dose-dependent manner (threshold: 3 x 10(-8) M; EC50 1.5 x 10(-6) M). The maximal rate of 5-HT-induced protein secretion was 2.2 +/- 0.2 mu g/min. Increasing intracellular Ca2+ or cAMP by bath application of ionomycin (5 mu M), db cAMP (10 mM), forskolin (100 mu M) or IBMX (100 mu M), respectively, stimulated protein secretion at significantly lower rates, whereas db cGMP (1 mM) did not activate protein secretion. The high rates and the kinetics of 5-HT-induced protein secretion could only be mimicked by either applying forskolin together with IBMX (with or without ionomycin) or by applying IBMX together with ionomycin. Our measurements suggest that 5-HT-induced protein secretion is mediated by an elevation of [cAMP](i) and that Ca2+ may function as a co-agonist and augment the rate of protein secretion. (c) 2005 Elsevier Ltd. All rights reserved Y1 - 2005 SN - 0022-1910 ER - TY - JOUR A1 - Mustard, J. A. A1 - Kurshan, P. T. A1 - Hamilton, Ingrid S. A1 - Blenau, Wolfgang A1 - Mercer, Alison R. T1 - Developmental expression of a tyramine receptor gene in the brain of the honey bee, Apis mellifera Y1 - 2005 ER -