The catecholamines norepinephrine and epinephrine are important regulators of
vertebrate physiology. Insects such as honeybees do not synthesize these neuroactive substances.
Instead, they use the phenolamines tyramine and octopamine for similar physiological functions.
These biogenic amines activate specific members of the large protein family of G protein-coupled
receptors (GPCRs). Based on molecular and pharmacological data, insect octopamine receptors
were classified as either - or -adrenergic-like octopamine receptors. Currently, one - and four
-receptors have been molecularly and pharmacologically characterized in the honeybee. Recently,
an 2-adrenergic-like octopamine receptor was identified in Drosophila melanogaster (DmOct2R).
This receptor is activated by octopamine and other biogenic amines and causes a decrease in
intracellular cAMP ([cAMP]i). Here, we show that the orthologous receptor of the honeybee
(AmOct2R), phylogenetically groups in a clade closely related to human 2-adrenergic receptors.
When heterologously expressed in an eukaryotic cell line, AmOct2R causes a decrease in [cAMP]i.
The receptor displays a pronounced preference for octopamine over tyramine. In contrast to
DmOct2R, the honeybee receptor is not activated by serotonin. Its activity can be blocked eciently
by 5-carboxamidotryptamine and phentolamine. The functional characterization of AmOct2R now
adds a sixth member to this subfamily of monoaminergic receptors in the honeybee and is an important
step towards understanding the actions of octopamine in honeybee behavior and physiology.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:89220 |
| Date | 24 January 2024 |
| Creators | Blenau, Wolfgang, Wilms, Joana Alessandra, Balfanz, Sabine, Baumann, Arnd |
| Publisher | MDPI |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 9334 |
Page generated in 0.0025 seconds