Biomaterial Database

Mediation by G protein betagamma subunits of the opioid stimulation of adenylyl cyclase activity in rat olfactory bulb. 1999

M C Olianas, and P Onali

Department of Neuroscience, University of Cagliari, Italy. onali@unica.it

In the rat olfactory bulb, activation of opioid receptors enhances basal adenylyl cyclase (EC 4.6.1.1) activity and potentiates enzyme stimulation by Gs-coupled neurotransmitter receptors in a pertussis toxin-sensitive manner. In the present study, we investigated the involvement of G protein betagamma subunits by examining the effects of betagamma scavengers and exogenously added betagamma subunits of transducin (betagamma(t)). The QEHA fragment of type II adenylyl cyclase (50 microM), a peptide that binds to and inactivates betagamma, inhibited the maximal stimulation of adenylyl cyclase activity elicited by Leu-enkephalin (Leu-enk) by about 50%. Similarly, the GDP-bound form of the alpha subunit of transducin (5 nM-1.5 microM), another betagamma scavenger, reduced both the opioid stimulation of basal adenylyl cyclase activity and the potentiation of vasoactive intestinal peptide-stimulated enzyme activity. Under the same experimental conditions, these agents failed to affect the stimulation of the enzyme activity elicited by activation of beta-adrenergic receptors with 1-isoproterenol. Moreover, the addition of betagamma(t)(400 nM) stimulated basal adenylyl cyclase by 80%, and this effect was not additive with that produced by Leu-enk. The data indicate that opioids enhance adenylyl cyclase activity in rat olfactory bulb by promoting the release of betagamma subunits from pertussis toxin-sensitive G proteins Gi/Go.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009294	Narcotics	Agents that induce NARCOSIS. Narcotics include agents that cause somnolence or induced sleep (STUPOR); natural or synthetic derivatives of OPIUM or MORPHINE or any substance that has such effects. They are potent inducers of ANALGESIA and OPIOID-RELATED DISORDERS.	Analgesics, Narcotic,Narcotic Analgesics,Narcotic,Narcotic Effect,Narcotic Effects,Effect, Narcotic,Effects, Narcotic
D009830	Olfactory Bulb	Ovoid body resting on the CRIBRIFORM PLATE of the ethmoid bone where the OLFACTORY NERVE terminates. The olfactory bulb contains several types of nerve cells including the mitral cells, on whose DENDRITES the olfactory nerve synapses, forming the olfactory glomeruli. The accessory olfactory bulb, which receives the projection from the VOMERONASAL ORGAN via the vomeronasal nerve, is also included here.	Accessory Olfactory Bulb,Olfactory Tract,Bulbus Olfactorius,Lateral Olfactory Tract,Main Olfactory Bulb,Olfactory Glomerulus,Accessory Olfactory Bulbs,Bulb, Accessory Olfactory,Bulb, Main Olfactory,Bulb, Olfactory,Bulbs, Accessory Olfactory,Bulbs, Main Olfactory,Bulbs, Olfactory,Glomerulus, Olfactory,Lateral Olfactory Tracts,Main Olfactory Bulbs,Olfactorius, Bulbus,Olfactory Bulb, Accessory,Olfactory Bulb, Main,Olfactory Bulbs,Olfactory Bulbs, Accessory,Olfactory Bulbs, Main,Olfactory Tract, Lateral,Olfactory Tracts,Olfactory Tracts, Lateral,Tract, Lateral Olfactory,Tract, Olfactory,Tracts, Lateral Olfactory,Tracts, Olfactory
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D000067956	Adenylyl Cyclase Inhibitors	Compounds that bind to and inhibit the action of ADENYLYL CYCLASES.	Adenylate Cyclase Inhibitors,Cyclase Inhibitors, Adenylate,Cyclase Inhibitors, Adenylyl,Inhibitors, Adenylate Cyclase,Inhibitors, Adenylyl Cyclase
D000262	Adenylyl Cyclases	Enzymes of the lyase class that catalyze the formation of CYCLIC AMP and pyrophosphate from ATP.	Adenyl Cyclase,Adenylate Cyclase,3',5'-cyclic AMP Synthetase,Adenylyl Cyclase,3',5' cyclic AMP Synthetase,AMP Synthetase, 3',5'-cyclic,Cyclase, Adenyl,Cyclase, Adenylate,Cyclase, Adenylyl,Cyclases, Adenylyl,Synthetase, 3',5'-cyclic AMP
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D015293	Transducin	A heterotrimeric GTP-binding protein that mediates the light activation signal from photolyzed rhodopsin to cyclic GMP phosphodiesterase and is pivotal in the visual excitation process. Activation of rhodopsin on the outer membrane of rod and cone cells causes GTP to bind to transducin followed by dissociation of the alpha subunit-GTP complex from the beta/gamma subunits of transducin. The alpha subunit-GTP complex activates the cyclic GMP phosphodiesterase which catalyzes the hydrolysis of cyclic GMP to 5'-GMP. This leads to closure of the sodium and calcium channels and therefore hyperpolarization of the rod cells.	G-Protein, Inhibitory Gt,Gt, Transducin G-Protein,alpha-Transducin,beta-Transducin,gamma-Transducin,Transducin G-Protein (Gt),Transducin, alpha Subunit,Transducin, beta Subunit,Transducin, gamma Subunit,G Protein, Inhibitory Gt,G-Protein Gt, Transducin,Gt G-Protein, Inhibitory,Gt, Transducin G Protein,Inhibitory Gt G-Protein,Transducin G-Protein Gt,alpha Subunit Transducin,alpha Transducin,beta Subunit Transducin,beta Transducin,gamma Subunit Transducin,gamma Transducin
D015398	Signal Transduction	The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.	Cell Signaling,Receptor-Mediated Signal Transduction,Signal Pathways,Receptor Mediated Signal Transduction,Signal Transduction Pathways,Signal Transduction Systems,Pathway, Signal,Pathway, Signal Transduction,Pathways, Signal,Pathways, Signal Transduction,Receptor-Mediated Signal Transductions,Signal Pathway,Signal Transduction Pathway,Signal Transduction System,Signal Transduction, Receptor-Mediated,Signal Transductions,Signal Transductions, Receptor-Mediated,System, Signal Transduction,Systems, Signal Transduction,Transduction, Signal,Transductions, Signal