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Molecular identification and functional characterization of an adenylyl cyclase from the honeybee
Author(s) -
Wachten Sebastian,
Schlenstedt Jana,
Gauss Renate,
Baumann Arnd
Publication year - 2006
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2006.03666.x
Subject(s) - adenylyl cyclase , biology , adcy9 , adcy10 , gs alpha subunit , signal transduction , camp dependent pathway , g protein , forskolin , mushroom bodies , adcy6 , biochemistry , second messenger system , receptor , biogenic amine , adcy3 , microbiology and biotechnology , gene , neurotransmitter , drosophila melanogaster
Cyclic AMP (cAMP) serves as an important messenger in virtually all organisms. In the honeybee ( Apis mellifera ), cAMP‐dependent signal transduction has been implicated in behavioural processes as well as in learning and memory. Key components of cAMP‐signalling cascades are adenylyl cyclases. However, the molecular identities and biochemical properties of adenylyl cyclases are completely unknown in the honeybee. We have cloned a cDNA (Am ac 3) from honeybee brain that encodes a membrane‐bound adenylyl cyclase. The Am ac 3 gene is an orthologue of the Drosophila ac 39E gene. The corresponding proteins share an overall amino acid similarity of approximately 62%. Phylogenetically, AmAC3 belongs to group 1 adenylyl cyclases. Heterologously expressed AmAC3 displays basal enzymatic activity and efficient coupling to endogenous G protein signalling pathways. Stimulation of β‐adrenergic receptors induces AmAC3 activity with an EC 50 of about 3.1 µ m . Enzymatic activity is also increased by forskolin (EC 50 approximately 15 µ m ), a specific agonist of membrane‐bound adenylyl cyclases. Similar to certain biogenic amine receptor genes of the honeybee, Am ac 3 transcripts are expressed in many somata of the brain, especially in mushroom body neurones. These results suggest that the enzyme serves in biogenic amine signal transduction cascades and in higher brain functions that contribute to learning and memory of the bee.