@misc{TroppmannBalfanzKrachetal.2014, author = {Troppmann, Britta and Balfanz, Sabine and Krach, Christian and Baumann, Arnd and Blenau, Wolfgang}, title = {Characterization of an Invertebrate-Type Dopamine Receptor of the American Cockroach, Periplaneta americana}, series = {International journal of molecular sciences}, volume = {15}, journal = {International journal of molecular sciences}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {1422-0067}, doi = {10.3390/ijms15010629}, pages = {629 -- 653}, year = {2014}, abstract = {We have isolated a cDNA coding for a putative invertebrate-type dopamine receptor (Peadop2) from P. americana brain by using a PCR-based strategy. The mRNA is present in samples from brain and salivary glands. We analyzed the distribution of the PeaDOP2 receptor protein with specific affinity-purified polyclonal antibodies. On Western blots, PeaDOP2 was detected in protein samples from brain, subesophageal ganglion, thoracic ganglia, and salivary glands. In immunocytochemical experiments, we detected PeaDOP2 in neurons with their somata being located at the anterior edge of the medulla bilaterally innervating the optic lobes and projecting to the ventro-lateral protocerebrum. In order to determine the functional and pharmacological properties of the cloned receptor, we generated a cell line constitutively expressing PeaDOP2. Activation of PeaDOP2-expressing cells with dopamine induced an increase in intracellular cAMP. In contrast, a C-terminally truncated splice variant of this receptor did not exhibit any functional property by itself. The molecular and pharmacological characterization of the first dopamine receptor from P. americana provides the basis for forthcoming studies focusing on the significance of the dopaminergic system in cockroach behavior and physiology.}, language = {en} } @misc{TroppmannBalfanzBaumannetal.2010, author = {Troppmann, Britta and Balfanz, Sabine and Baumann, Arnd and Blenau, Wolfgang}, title = {Inverse agonist and neutral antagonist actions of synthetic compounds at an insect 5-HT1 receptor}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-44346}, year = {2010}, abstract = {Background and purpose: 5-Hydroxytryptamine (5-HT) has been shown to control and modulate many physiological and behavioural functions in insects. In this study, we report the cloning and pharmacological properties of a 5-HT1 receptor of an insect model for neurobiology, physiology and pharmacology. Experimental approach: A cDNA encoding for the Periplaneta americana 5-HT1 receptor was amplified from brain cDNA. The receptor was stably expressed in HEK 293 cells, and the functional and pharmacological properties were determined in cAMP assays. Receptor distribution was investigated by RT-PCR and by immunocytochemistry using an affinity-purified polyclonal antiserum. Key results: The P. americana 5-HT1 receptor (Pea5-HT1) shares pronounced sequence and functional similarity with mammalian 5-HT1 receptors. Activation with 5-HT reduced adenylyl cyclase activity in a dose-dependent manner. Pea5-HT1 was expressed as a constitutively active receptor with methiothepin acting as a neutral antagonist, and WAY 100635 as an inverse agonist. Receptor mRNA was present in various tissues including brain, salivary glands and midgut. Receptor-specific antibodies showed that the native protein was expressed in a glycosylated form in membrane samples of brain and salivary glands. Conclusions and implications: This study marks the first pharmacological identification of an inverse agonist and a neutral antagonist at an insect 5-HT1 receptor. The results presented here should facilitate further analyses of 5-HT1 receptors in mediating central and peripheral effects of 5-HT in insects.}, language = {en} }