A-kinase-anchoring proteins (AKAPs) are scaffold proteins which compartmentalize protein kinase A (PKA, cAMP-dependent protein kinase) and other enzymes to specific subcellular sites. The spatiotemporal control of these enzymes by AKAPs is important for cellular function like cell growth and development etc. Hence, it is important to understand the basic function of AKAPs and their functional domains. However, diverse names, function, cellular localizations and many members of AKAPs increase difficulties when researchers search appropriate AKAPs for their experimental purpose. Nevertheless, there was no previous AKAPs-related database regardless of their important cellular functions and difficulty of finding appropriate AKAPs. So, we developed AKAPs database (AKAPDB), which contains their sequence information, functions and other information derived from prediction programs and other databases. Therefore, we propose that AKAPDB can be an important tool to researchers in the related fields. AKAPDB is available via the internet at http://plaza3.snu.ac.kr/akapdb/
Cyclic AMP-Dependent Protein Kinases ; Growth and Development ; Internet ; Proteins

Nuclear factor kappaB (NF- kappaB) activation is modulated by various protein kinases. Activation of NF- kappaB is known to be important in the regulation of cell viability. The present study investigated the effect of inhibitors of protein tyrosine kinase (PTK), protein kinase C (PKC) and protein kinase A (PKA) on NF- kappaB activity and the viability of bovine cerebral endothelial cells (BCECs). In serum-deprivation-induced BCEC death, low doses of TNF alpha showed a protective effect. TNF alpha induced NF- kappaB activation within 4 h in serum-deprivation. PTK inhibitors (herbimycin A and genistein) and PKC inhibitor (calphostin C) prevented NF- kappaB activation stimulated by TNF alpha. Likewise, these inhibitors prevented the protective effect of TNF alpha. In contrast to TNF alpha-stimulated NF- kappaB activity, basal NF- kappaB activity of BCECs in media containing serum was suppressed only by calphostin C, but not by herbimycin A. As well BCEC death was also induced only by calphostin C in serum-condition. H 89, a PKA inhibitor, did not affect the basal and TNF alpha-stimulated NF- kappaB activities and the protective effect of TNF alpha on cell death. These data suggest that modulation of NF- kappaB activation could be a possible mechanism for regulating cell viability by protein kinases in BCECs.
Cell Death* ; Cell Survival ; Cyclic AMP-Dependent Protein Kinases ; Endothelial Cells* ; Protein Kinase C ; Protein Kinases* ; Protein-Tyrosine Kinases

A case of Carney complex in a Korean patient is presented. The patient had the characteristics of Carney complex including skin lesions, positive family history, and multiple myxomas including a superficial angiomyxoma in the perianal area. An extensive genetic analysis revealed a novel mutation in the protein kinase A type I-a regulatory subunit (PRKAR1A) gene, but not in the phosphodiesterase type 11A (PDE11A) gene. This is the first case wherein extensive genetic studies were performed in a patient with Carney complex in Korea.
Carney Complex ; Cyclic AMP-Dependent Protein Kinases ; Humans ; Korea ; Myxoma ; Skin

Carney complex is an autosomal dominant disorder that occurs due to a mutation in PRKAR1A, which encodes protein kinase A. The clinical features are multiple endocrine gland neoplasms, skin tumors, pigmented skin lesions, myxomas, and schwannomas. In Carney complex, the cardiac myxoma is a common co-morbidity. It occurs in multiples, during young age, regardless of gender and cardiac chamber and is known to recur frequently. Therefore there are high risks of adhesion and massive bleeding due to repeated surgeries. Such surgical risks account for over 50% of disease-specific mortality of Carney complex patients. Here, we present anesthetic experiences of myxoma removal surgery in two patients with Carney complex.
Anesthesia ; Carney Complex ; Cyclic AMP-Dependent Protein Kinases ; Endocrine Gland Neoplasms ; Hemorrhage ; Humans ; Myxoma ; Neurilemmoma ; Skin

Objective To observe the effect of low-frequency pulsed electromagnetic fields(PEMFs) on bone formation in rat osteoblasts(ROBs) and explore the mechanism of action of the cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)/cyclic adenosine effect binding protein(CREB) signaling pathway.Methods The skulls of newborn Wistar rats were harvested,and the ROBs were obtained by multiple enzymatic digestion methods for subculture. After treatment with 50 Hz 0.6 mT PEMFs for 3,6,and 9 days,the alkaline phosphatase(ALP) concentration in ROBs was detected;after 0,15,30,60,90,and 120 min,the expression of bone formation-related factor(RUNX2),the protein expression of osteogenesis-associated transcription factor(OSX),the cAMP concentration,as well as the protein expressions of p-PKA,p-CREB,and CREB were detected. The p-CREB nuclear translocation was observed. After interference with IFT88 by RNA interference,the expressions of RUNX2,OSX,p-PKA,and p-CREB protein in ROBs were detected.Results After treatment with PEMFs for 3,6,and 9 days,the ALP activity values in ROBs were 24.356±4.911,37.688±2.151,and 39.922±5.486,respectively,which were significantly higher than 18.531±2.401(P=0.0121),33.675±4.366(P=0.0324),and 36.574±1.339(P=0.0134) in the control groups. RUNX2 and OSX activities in ROBs were significantly higher than untreated group after PEMFs treatment for 30(P=0.0042 and P=0.0058),60(P=0.0097 and P=0.0079),and 90 min(P=0.0083 and P=0.0098). After PEMFs treatment for 30(P=0.0012) and 60 min(P=0.0035),the cAMP concentrations in ROBs were significantly higher than that in untreated group. After PEMFs treatment for 15(P=0.0018),30(P=0.0087),90(P=0.0250),and 120 min(P=0.0350),the p-PKA levels in ROBs were significantly higher than that in the untreated group. After PEMFs treatment for 15(P=0.0075),30(P=0.0017),60(P=0.0074),and 90 min(P=0.0096),the level of p-CREB in the ROBs was significantly higher than in the untreated group. After PEMFs treatment of ROBs for 15 min,CREB phosphorylated and accumulated in the nuclei. PKA and p-PKA were co-localized with primary cilia and stained,and it was found that p-PKA was localized on the primary cilia. After the primary cilia was removed by RNA interference,the protein expression levels of p-PKA(F=78.602,P=0.0270),p-CREB(F=76.082,P=0.0089),RUNX2(F=41.064,P=0.0230) and OSX(F=57.524,P=0.0310) were significantly lower than those of the non-interfered group.Conclusion PEMFs promote bone formation in ROBs by activating the primary cilia-associated cAMP/PKA/CREB signaling pathway.
Animals ; Cyclic AMP-Dependent Protein Kinases ; Electromagnetic Fields ; Osteoblasts ; Osteogenesis ; Rats ; Rats, Wistar

OBJECTIVE: To investigate the effect of protein kinase A (PKA) activation on aggregation funetion of platelets in vitro. METHODS: The peripheral blood of healthy adults were collected, and the washed platelets were gained from collected peripheral blood. The washed platelets were treated with PKA activator Forskolin, then the platelet aggregation was induced by using Ristocetin, Thrombin, Collagen and ADP respectively, the platelet aggregation level was detected by the platelet aggregator. RESULTS: Compared with the controls, 5 μmol/L forskolin significantly inhibited ADP and collagen-induced platelet aggregation (P＜0.001), and showed mild inhibiting effect on Thrombin-induced platelet aggregation (P＜0.05). 2.5-10 μmol/L forskolin significantly inhibited ADP and Collagen -induced platelet aggregation (P＜0.001); but not showed significantly inhibitory effects on Ristocetin-induced platelet aggregation (P＞0.05). CONCLUSION PKA activation inhibits agonists-induced platelet aggregation.
Blood Platelets ; Cyclic AMP-Dependent Protein Kinases ; Humans ; Platelet Aggregation ; Platelet Aggregation Inhibitors ; Ristocetin ; Thrombin

Cilostazol is a selective inhibitor of phosphodiesterase 3 that increases intracellular cAMP levels and activates protein kinase A, thereby inhibiting vascular smooth muscle cell (VSMC) proliferation. We investigated whether AMP-activated protein kinase (AMPK) activation induced by heme oxygenase-1 (HO-1) is a mediator of the beneficial effects of cilostazol and whether cilostazol may prevent cell proliferation and reactive oxygen species (ROS) production by activating AMPK in VSMC. In the present study, we investigated VSMC with various concentrations of cilostazol. Treatment with cilostazol increased HO-1 expression and phosphorylation of AMPK in a dose- and time-dependent manner. Cilostazol also significantly decreased platelet-derived growth factor (PDGF)-induced VSMC proliferation and ROS production by activating AMPK induced by HO-1. Pharmacological and genetic inhibition of HO-1 and AMPK blocked the cilostazol-induced inhibition of cell proliferation and ROS production.These data suggest that cilostazol-induced HO-1 expression and AMPK activation might attenuate PDGF-induced VSMC proliferation and ROS production.
AMP-Activated Protein Kinases ; Cell Proliferation ; Cyclic AMP-Dependent Protein Kinases ; Heme ; Heme Oxygenase-1 ; Muscle, Smooth, Vascular ; Phosphorylation ; Platelet-Derived Growth Factor ; Reactive Oxygen Species ; Tetrazoles

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the Na(+)-K(+)-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain (3.0 micromol/L) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 (3.0 micromol/L), an inhibitor for reverse mode of Na(+)-Ca(2+) exchangers (NCX), but did not by L-type Ca2+ channel blocker nifedipine (1.0 micromol/L) or protein kinase A (PKA) selective inhibitor H-89 (3.0 micromol/L). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline (100.0 micromol/L), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP (0.5 micromol/L) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 (30 micromol/L), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.
8-Bromo Cyclic Adenosine Monophosphate ; Adenosine ; Cardiomegaly ; Colforsin ; Cyclic AMP-Dependent Protein Kinases ; Endothelin-1* ; Heart Diseases ; Nifedipine ; Ouabain* ; Phosphotransferases ; Protein Kinases

This study was performed to investigate the signaling pathway that mediates cyclic AMP (cAMP)-induced inhibition of histone deacetylase 8 (HDAC8) degradation, and the effect and underlying mechanisms of the resulting increase in HDAC8 expression on cisplatin-induced apoptosis in lung cancer cells. cAMP signaling increased HDAC8 expression via a protein kinase A (PKA)-independent pathway in H1299 non-small cell lung cancer cells. However, treatment with a selective activator of an exchange protein that was activated by cAMP (Epac) increased HDAC8 expression, and Epac2 inhibition abolished the isoproterenol (ISO)-induced increase in HDAC8 expression. ISO and the Epac activator activated Rap1, and Rap1A activation increased HDAC8 expression; moreover, inhibition of Rap1A with a dominant negative Rap1A or by shRNA-mediated knockdown abolished the ISO-induced increase in HDAC8 expression. Activation of cAMP signaling and Rap1A decreased the activating phosphorylation of Akt. Akt inhibition with a pharmacological inhibitor or expression of a dominant negative Akt inhibited the MKK4/JNK pathway and increased HDAC8 expression. The Akt inhibitor-induced increase in HDAC8 expression was abolished by pretreatment with proteasomal or lysosomal inhibitors. The ISO treatment increased cisplatin-induced apoptosis, which was abolished by HDAC8 knockdown. Exogenous HDAC8 expression increased cisplatin-induced apoptosis and decreased TIPRL expression, and the knockdown of TIPRL increased the apoptosis of cisplatin-treated cells. The ISO treatment decreased cisplatin-induced transcription of the TIPRL gene in a HDAC8-dependent manner. In conclusion, the Epac–Rap1–Akt pathway mediates cAMP signaling-induced inhibition of JNK-dependent HDAC8 degradation, and the resulting HDAC8 increase augments cisplatin-induced apoptosis by repressing TIPRL expression in H1299 lung cancer cells.
Apoptosis ; Carcinoma, Non-Small-Cell Lung ; Cyclic AMP ; Cyclic AMP-Dependent Protein Kinases ; Histone Deacetylases* ; Histones* ; Isoproterenol ; Lung Neoplasms* ; Lung* ; Phosphorylation

B/K protein is a novel protein containing double C2-like domains. We examined the specific signaling pathway that regulates the transcription of B/K in PC12 cells. When the cells were treated with forskolin (50microM), B/K mRNA and protein levels were time-dependently decreased, reaching the lowest level at 3 or 4 hr, and thereafter returning to the control level. Chemicals such as dibutyryl-cAMP, cell- permeable cyclic AMP (cAMP) analogue and CGS21680, adenosine receptor A2A agonist, also repressed the B/K transcription. However, 1, 9-dideoxyforskolin did not show inhibitory effect on B/K transcription, suggesting direct involvement of cAMP in the forskolin-induced inhibition of B/K transcription. Effect of forskolin, dibutyryl cAMP and CGS21680 was significantly reduced in PKA-deficient PC12 cell line (PC12-123.7). One cAMP-response element (CRE) -like sequence (B/K CLS) was found in the promoter region of B/K DNA, and electrophoretic mobility shift assay indicated its binding to CREM and CREB. Forskolin significantly suppressed the promoter activity in CHO-K1 cells transfected with the constructs containing B/K CLS, but not with the construct in which B/K CLS was mutated (AC: TG). Taken together, we suggest that the transcription of B/K gene in PC12 cells may be regulated by PKA-dependent mechanism.
Animals ; Colforsin ; Cyclic AMP ; Cyclic AMP-Dependent Protein Kinases ; DNA ; Electrophoretic Mobility Shift Assay ; PC12 Cells* ; Promoter Regions, Genetic ; Receptors, Purinergic P1 ; RNA, Messenger