Localization Of Cyclic AMP Research Articles

Molecular Basis of AKAP Specificity for PKA Regulatory Subunits

Localization of cyclic AMP (cAMP)-dependent protein kinase (PKA) by A kinase-anchoring proteins (AKAPs) restricts the action of this broad specificity kinase. The high-resolution crystal structures of the docking and dimerization (D/D) domain of the RIIalpha regulatory subunit of PKA both in the apo state and in complex with the high-affinity anchoring peptide AKAP-IS explain the molecular basis for AKAP-regulatory subunit recognition. AKAP-IS folds into an amphipathic alpha helix that engages an essentially preformed shallow groove on the surface of the RII dimer D/D domains. Conserved AKAP aliphatic residues dominate interactions to RII at the predominantly hydrophobic interface, whereas polar residues are important in conferring R subunit isoform specificity. Using a peptide screening approach, we have developed SuperAKAP-IS, a peptide that is 10,000-fold more selective for the RII isoform relative to RI and can be used to assess the impact of PKA isoform-selective anchoring on cAMP-responsive events inside cells.

Neurochemical differences in the superior cervical ganglion of the spontaneously hypertensive rat stroke-prone variant

The localization and distribution of catecholamines, selected neuropeptides, and the cyclic nucleotide second messengers has been determined in the superior cervical ganglion of the stroke-prone variant of the spontaneously hypertensive rat (SHR) and its normotensive Wistar-kyoto (WKY) control. Significant alteration in the frequency of occurrence of dopaminergic small intensely fluorescent cell clusters was seen in the stroke-prone variant of the SHR. The immunofluorescent localization of cyclic AMP (cAMP) and cyclic GMP (cGMP) were also changed in the stroke-prone variant, as was the immunofluorescent staining quantity of the neuropeptides somatostatin and substance P. The morphological pattern of staining for the various compounds in the normotensive control (WKY) was equivalent to the Sprague-Dawley rat strain. The implications of the altered neurochemistry in the superior cervical ganglion on the high blood pressure, and the predisposition for stroke in this strain are discussed.

Immunohistochemical localization of cyclic AMP and ultrastructural demonstration of adenylate cyclase activity in the testis of Esox lucius at time of spermiation.

In the testis of Esox lucius at the time of spermiation, activity of cyclic adenosine 3',5'-monophosphate (cAMP) was immunocytochemically localized at the level of the Sertoli cells. In these cells adenylate cyclase activity was also ultracytochemically demonstrated by using adenylyl imidodiphosphate as a substrate. Reaction products of adenylate cyclase were primarily detectable on the basal and adluminal plasma membranes and on the surface of protrusions of the cell body into the lumen.

Prostaglandins and intracellular cyclic AMP in respiratory secretory cells.

Prostaglandins are known to affect ion transport and mucus secretion in the trachea, and at least part of their effect is thought to be mediated by cyclic AMP. Because no prostaglandin receptor assay is currently available, we have used an immunocytochemical probe for the intracellular localization of cyclic AMP to identify those specific cell types in dog and cat trachea that respond to prostaglandins. Using tracheal explants similar to those used by other investigators for in vitro studies of ion transport and glycoprotein secretion, we examined the effect of endogenous and exogenous prostaglandins on immunoreactive cyclic AMP. Endogenous prostaglandins, which may be secreted in response to minor distortion of tissue membranes, stimulated immunoreactive cyclic AMP in ciliated epithelial cells and in both serous and mucous submucosal gland cells. This was not observed in tissues assayed 60 min after dissection, or dissected in the presence of indomethacin or of BW755C. Exogenous prostaglandin E1 increased cyclic AMP in these same cell types. We conclude that prostaglandins stimulate cyclic AMP in specific cell types in the trachea, and that endogenous prostaglandins play a major role in many in vitro preparations.

Immunocytochemical localization of cyclic AMP and cyclic GMP in rat ovarian tissue.

Immunocytochemical localization of cyclic AMP and cyclic GMP in rat ovarian tissue.

Cyclic Adenosine 3’,5’-Monophosphate Levels in Response to Norepinephrine in Rectum of Postnatal Rats*

Age-related changes in cyclic adenosine 3’,5’-monophosphate levels in response to norepinephrine (NE) in the rectum of postnatal rats and the localization of cyclic AMP in the rectum were studied. During the first 2 weeks after birth, the basal levels of cyclic AMP were high, NE responses to cyclic AMP contents were minimal and thereafter, the basal cyclic AMP levels rapidly declined, while NE response significantly increased compared to those seen in tissues from adult rats. Furthermore, cyclic AMP immunofluorescence was visualized in smooth muscle and postganglionic neurons of the myenteric plexus. NE application produced an increase of cyclic AMP immunofluorescence in smooth muscle. These results indicate that NE response to cyclic AMP levels in rat rectum is age-dependent and suggest that the majority of β-adrenoceptors associated with cyclic AMP generating system are localized in the smooth muscle of rat rectum.

Cyclic adenosine 3',5'-monophosphate levels in response to norepinephrine in rectum of postnatal rats.

Age-related changes in cyclic adenosine 3',5'-monophosphate levels in response to norepinephrine (NE) in the rectum of postnatal rats and the localization of cyclic AMP in the rectum were studied. During the first 2 weeks after birth, the basal levels of cyclic AMP were high, NE responses to cyclic AMP contents were minimal and thereafter, the basal cyclic AMP levels rapidly declined, while NE response significantly increased compared to those seen in tissues from adult rats. Furthermore, cyclic AMP immunofluorescence was visualized in smooth muscle and postganglionic neurons of the myenteric plexus. NE application produced an increase of cyclic AMP immunofluorescence in smooth muscle. These results indicate that NE response to cyclic AMP levels in rat rectum is age-dependent and suggest that the majority of beta-adrenoceptors associated with cyclic AMP generating system are localized in the smooth muscle of rat rectum.

71) - Localization of cyclic AMP in rat cerebral cortex: Immunocytochemical demonstration

71) - Localization of cyclic AMP in rat cerebral cortex: Immunocytochemical demonstration

Immunofluorescent Localization of Cyclic AMP in Developing Rat Testis

ABSTRACT. Cyclic 3′,5′-adenosine monophosphate (cAMP) was histochemically localized in frozen sections of testes from sexually maturing rats by a highly specific and reproducible indirect immunofluorescence technique. Testes from normal rats revealed two distinct cAMP staining patterns. The first fluorescence pattern (FP-I) was observed in all rats from 5 through 60 days of age and consisted of cAMP staining within interstitial cell nuclei and cytoplasm, seminiferous tubule walls, portions of Sertoli cell cytoplasm adjacent to the tubule walls, the cytoplasm of early germinal cells, and occasional nuclei of germinal and Sertoli cells adjacent to the tubule walls. The second fluorescence pattern (FP-II) observed in normal testes was noted only at 15 and 20 days of age and consisted of staining confined to the central portions of the seminiferous tubules at the presumptive site of lumen formation. Similar localization studies were carried out in animals depleted of germinal cells by irradiation shortly befo...

450. Localization of cyclic AMP in rabbit ovarian follicles and effects of LH and PGE 2

450. Localization of cyclic AMP in rabbit ovarian follicles and effects of LH and PGE 2