title: Cockroach GABAB receptor subtypes: molecular characterization, pharmacological properties and tissue distribution.
abstract: γ-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the central nervous system (CNS). Its effects are mediated by either ionotropic GABAA receptors or metabotropic GABAB receptors. GABAB receptors regulate, via Gi/o G-proteins, ion channels, and adenylyl cyclases. In humans, GABAB receptor subtypes are involved in the etiology of neurologic and psychiatric disorders. In arthropods, however, these members of the G-protein-coupled receptor family are only inadequately characterized. Interestingly, physiological data have revealed important functions of GABAB receptors in the American cockroach, Periplaneta americana. We have cloned cDNAs coding for putative GABAB receptor subtypes 1 and 2 of P. americana (PeaGB1 and PeaGB2). When both receptor proteins are co-expressed in mammalian cells, activation of the receptor heteromer with GABA leads to a dose-dependent decrease in cAMP production. The pharmacological profile differs from that of mammalian and Drosophila GABAB receptors. Western blot analyses with polyclonal antibodies have revealed the expression of PeaGB1 and PeaGB2 in the CNS of the American cockroach. In addition to the widespread distribution in the brain, PeaGB1 is expressed in salivary glands and male accessory glands. Notably, PeaGB1-like immunoreactivity has been detected in the GABAergic salivary neuron 2, suggesting that GABAB receptors act as autoreceptors in this neuron.
authors.affiliation: Institute of Biochemistry and Biology, Department of Animal Physiology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany. Electronic address: stefanie.blankenburg@slu.se.
authors.forename: S
authors.initials: S
authors.lastname: Blankenburg
authors.affiliation: Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Research Center Jülich, Forschungszentrum Jülich, 52425, Jülich, Germany. Electronic address: s.balfanz@fz-juelich.de.
authors.forename: S
authors.initials: S
authors.lastname: Balfanz
authors.affiliation: Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan. Electronic address: yhaya@ees.hokudai.ac.jp.
authors.forename: Y
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: NIBB Core Research Facilities, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan. Electronic address: shige@nibb.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Shigenobu
authors.affiliation: Laboratory of Ecological Genetics, Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan. Electronic address: miu@ees.hokudai.ac.jp.
authors.forename: T
authors.initials: T
authors.lastname: Miura
authors.affiliation: Institute of Biochemistry and Biology, Department of Animal Physiology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany. Electronic address: obaumann@uni-potsdam.de.
authors.forename: O
authors.initials: O
authors.lastname: Baumann
authors.affiliation: Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Research Center Jülich, Forschungszentrum Jülich, 52425, Jülich, Germany. Electronic address: a.baumann@fz-juelich.de.
authors.forename: A
authors.initials: A
authors.lastname: Baumann
authors.affiliation: Institut für Bienenkunde, Polytechnische Gesellschaft, Goethe-Universität Frankfurt am Main, FB Biowissenschaften, Karl-von-Frisch-Weg 2, 61440, Oberursel, Germany. Electronic address: wblenau@uni-koeln.de.
authors.forename: W
authors.initials: W
authors.lastname: Blenau
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D003058:Cockroaches / Q000235:genetics / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D058786:GABA-B Receptor Agonists / Q000494:pharmacology; D058788:GABA-B Receptor Antagonists / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D007150:Immunohistochemistry; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D010802:Phylogeny; D018080:Receptors, GABA-B / Q000235:genetics / Q000378:metabolism*; D012469:Salivary Glands / Q000378:metabolism; D014162:Transfection
chemical_list: D058786:GABA-B Receptor Agonists; D058788:GABA-B Receptor Antagonists; D019476:Insect Proteins; D018080:Receptors, GABA-B; D000242:Cyclic AMP
keywords: Adenylyl cyclase; Central nervous system; G-protein-coupled receptor; GABA(B) receptor; Periplaneta americana; Salivary gland