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  - JOUR
A1  - Heindorff, Kristoffer
A1  - Blenau, Wolfgang
A1  - Walz, Bernd
A1  - Baumann, Otto
T1  - Characterization of a Ca2+/calmodulin-dependent AC1 adenylyl cyclase in a non-neuronal tissue, the blowfly salivary gland
JF  - Cell calcium
N2  - Crosstalk between intracellular signalling pathways is a functionally important and widespread phenomenon in cell physiology across phyla. In the salivary gland of the blowfly, serotonin induces fluid secretion via parallel activation of both the InsP(3)/Ca2+ and the cAMP/PKA signalling pathways, which interact on multiple levels. We have determined the molecular identity of a link between both pathways that mediates a Ca2+-dependent rise of intracellular cAMP. Whereas hydrolysis of cAMP via phosphodiesterases is largely independent of Ca2+, cAMP synthesis by adenylyl cyclases (AC) is potentiated in a Ca2+/calmodulin (Ca2+/CaM)-dependent manner. The existence of a Ca2+/CaM-dependent AC is supported by physiological data and a molecular approach. We have cloned Cv rutabaga cDNA, encoding the first blowfly AC, and confirmed its expression in the salivary gland via reverse transcription followed by polymerase chain reaction. The putative gene product of Cv rutabaga is a Ca2+/CaM-dependent type I AC and shows highest homology to Rutabaga from Drosophila. Thus, a Ca2+/CaM-dependent AC serves as a link between the InsP(3)/Ca2+ and the cAMP/PKA signalling pathways in the salivary gland of the blowfly and might be important for the amplification and optimization of the secretory response.
KW  - Adenylyl cyclase
KW  - Phosphodiesterase
KW  - Crosstalk
KW  - Ca2+
KW  - cAMP
KW  - Intracellular signalling
KW  - Salivary gland
KW  - Calliphora vicina
KW  - Rutabaga
Y1  - 2012
U6  - https://doi.org/10.1016/j.ceca.2012.04.016
SN  - 0143-4160
VL  - 52
IS  - 2
SP  - 103
EP  - 112
PB  - Churchill Livingstone
CY  - Edinburgh
ER  -