The endogenous Ca-inhibitable adenylyl cyclase type VI of C6-2B glioma cells is regulated only by capacitative Ca entry and not by a substantial elevation of [Ca]i from either intracellular stores or via ionophoremediated Ca entry (Chiono, M., Mahey, R., Tate, G., and Cooper, D. M. F. (1995) J. Biol. Chem. 270, 1149–1155; Fagan, K. A., Mons, N., and Cooper, D. M. F. (1998) J. Biol. Chem. 273, 9...

Adenylyl cyclase superactivation, a phenomenon by which chronic activation of inhibitory Gi/o-coupled receptors leads to an increase in cAMP accumulation, is believed to play an important role as a compensatory response of the cAMP signaling system in the cell. However, to date, the mechanism by which adenylyl cyclase activity is regulated by chronic exposure to inhibitory agonists and the natu...

Type I adenylyl cyclase is a neurospecific enzyme that is stimulated by Ca2+ and calmodulin (CaM). This enzyme couples the Ca2+ and cyclic AMP (cAMP) regulatory systems in neurons, and it may play an important role for some forms of synaptic plasticity. Mutant mice lacking type I adenylyl cyclase show deficiencies in spatial memory and altered long-term potentiation (Z. Wu, S. A. Thomas, Z. Xia...

The Slr1991 adenylyl cyclase of the model prokaroyte Synechocystis PCC 6803 was stimulated 2-fold at 20 mM total C(i) (inorganic carbon) at pH 7.5 through an increase in k(cat). A dose response demonstrated an EC50 of 52.7 mM total C(i) at pH 6.5. Slr1991 adenylyl cyclase was activated by CO2, but not by HCO3-. CO2 regulation of adenylyl cyclase was conserved in the CyaB1 adenylyl cyclase of An...

While acute activation of G(i/o)-coupled receptors leads to inhibition of adenylyl cyclase, chronic activation of such receptors produces an increase in cyclic AMP accumulation, particularly evident upon withdrawal of the inhibitory agonist. This phenomenon has been referred to as adenylyl cyclase superactivation and is believed to play an important role in opiate addiction. Nine adenylyl cycla...

An intriguing development in the Gprotein signaling field has been the finding that not only the Ga subunit, but also Gbg subunits, affect a number of downstream target molecules. One of the downstream targets of Gbg is adenylyl cyclase, and it has been demonstrated that a number of isoforms of adenylyl cyclase can be either inhibited or stimulated by Gbg subunits. Until now, adenylyl cyclase t...

While acute activation of inhibitory Gi/o-coupled receptors leads to inhibition of adenylyl cyclase, chronic activation of such receptors leads to an increase in cAMP accumulation. This phenomenon, observed in many cell types, has been referred to as adenylyl cyclase superactivation. At this stage, the mechanism leading to adenylyl cyclase superactivation and the nature of the isozyme(s) respon...

The present study aimed to investigate the role of adenylyl cyclase activator in preventing diabetic nephropathy via antioxidant activity in rats. Biochemical parameters were performed to confirm Streptozotocin induced nephropathy in rats. Male Wistar rats were used in the present study to reduce the effect of estrogen. Rats were subjected to high fat diet (HFD) for two weeks followed by low do...

Chronic cannabinoid treatment results in the development of tolerance. Adenylyl cyclase superactivation, induced by chronic cannabinoid agonist administration, is regarded as one of the molecular mechanisms leading to tolerance. In the present study, the effect of cyclosporine on adenylyl cyclase superactivation after chronic exposure to WIN 55,212-2, a cannabinoid receptor agonist, was studied...

We have shown previously that decreasing intracellular calcium in the juxtaglomerular cells increases both cAMP formation and renin release. We hypothesized that this is because of an interaction between intracellular calcium and the calcium-inhibitable isoform of adenylyl cyclase, type-V. We used primary cultures of juxtaglomerular cells isolated from C-57/B6 mice at 70% to 80% confluence. Wes...