Vibrio vulnificus causes fatal infections in susceptible individuals. Group 1 capsular polysaccharide (CPS) operon is responsible for CPS expression, which plays an essential role in the pathogenesis of this pathogen. Cyclic AMP (cAMP) and cAMP receptor protein (crp) complex, which responds to glucose availability and functions as a global regulator, has been known to affect CPS production in this pathogen. This study was undertaken to experimentally verify whether cAMP-Crp directly or indirectly affects CPS production. A mutation in cyaA encoding adenylate cyclase, which is required for cAMP biosynthesis, inhibited V. vulnificus growth and changed opaque colonies to translucent colonies, and these changes were recovered by complementing cyaA or by adding exogenous cAMP. A mutation in crp encoding Crp also inhibited V. vulnificus growth and changed opaque colonies to translucent colonies, and these changes were recovered by complementing crp. Moreover, the crp or cyaA mutation decreased the susceptibility of V. vulnificus against NaOCl. The crp mutation reduced the transcription levels of group 1 CPS operon on a per cell basis. Glucose addition in the absence of Crp stimulated V. vulnificus growth, changed translucent colonies to opaque colonies, and increased the transcription levels of group 1 CPS operon. These results indicate that cAMP or Crp is indirectly involved in optimal CPS production by positively affecting metabolism or V. vulnificus growth rather than by directly controlling the expression of group 1 CPS operon.
Adenylyl Cyclases ; Complement System Proteins ; Cyclic AMP Receptor Protein ; Cyclic AMP* ; Glucose ; Metabolism ; Operon ; Vibrio vulnificus

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

The movement of teeth during orthodontic treatment requires bone remodeling process in periodontal tissue. To find out the changes occuring in the cell itself, mechanical force was applied to the cultured periodontal ligament cells. Following results were obtained from measuring the changes in cyclic AMP and PGE2, 3H thymidine incorporation amount in time lapse after application of mechanical force. 1. When mechanical force was applied to cultured PDL cells, the amount of cAMP in cells were increased significantly after 15 min. of force application, but were decreased gradually as time lapsed. 2. When mechanical force was applied to cultured PDL cells, the amount of PGE2 were increased at 20, 40, 60 min. and was significantly increased at 20 min. 3. When mechanical force was applied to cultured PDL cells, the amount of 3H-thymidine incorporation was some increased, but was not statistically significant.
Bone Remodeling ; Cyclic AMP ; Dinoprostone ; Periodontal Ligament* ; Thymidine ; Tooth

Humans ; Mutation ; Cyclic AMP-Dependent Protein Kinase Catalytic Subunits/genetics*

Cyclic adenosine monophosphate (cAMP) is one of the significant and conserved second messengers in mammals, and it participates in regulating the developmental and physiological functions of various organs and tissues through transducting extracellular signals. Studies have shown that the process of meiosis in female mammalian oocytes is closely related to the level of cAMP and strictly regulated. In oocytes, cAMP is mainly synthesized by adenylate cyclase 3 (AC3) and degraded by phosphodiesterase 3A (PDE3A), both of which jointly regulate the level of cAMP in oocytes and play important roles in the follicular development and oogenesis of female ovaries. It has been well illuminated that high level of cAMP in the cytoplasm of oocytes in growing follicles could maintain the arrest of the first meiotic of oocytes for a long time. The oocytes will resume meiosis and mature either when the synthesis of cAMP is down-regulated, or when cAMP is degraded by PDE3A. In recent years, the novo physiological functions of cAMP in oogenesis have been reported. To better understand the regulatory role and mechanism of cAMP in mammalian gametogenesis, this paper reviews the relevant research regarding the relationship between cAMP and germ cell development.
Adenosine Monophosphate ; Animals ; Cyclic AMP ; Female ; Mammals ; Meiosis ; Oocytes ; Oogenesis

The cyclic AMP receptor protein (CRP) complexed with cyclic AMP (CRP.cAMP) regulates expression of many genes by binding to sites at or near many promoters of Escherichia coli. The regulatory effect of CRP.cAMP was studied by in vitro transcription assay with lacUV5 promoter derivatives that have the CRP binding site at different locations (-56 to -69 from the transcription start site of lacUV5 promoter) upstream of the promoter. The CRP binding site itself influenced differently on the promoter activity depending on the distances from the promoter. Depending on the helix phasing of the CRP.cAMP relative to RNA polymerase CRP.cAMP activated, repressed or had no effect on the promoter. These results imply that a regulator is not a dedicated protein for repression or activation but that any regulator may have a potential of dual functionalities when it is under appropriate condition.
Binding Sites ; Cyclic AMP ; Cyclic AMP Receptor Protein ; DNA-Directed RNA Polymerases ; Escherichia coli* ; Escherichia* ; Repression, Psychology ; Transcription Initiation Site

Taurochenodeoxycholic acid (TCDCA) is one of the main effective components of bile acid, playing critical roles in apoptosis and immune responses through the TGR5 receptor. In this study, we reveal the interaction between TCDCA and TGR5 receptor in TGR5-knockdown H1299 cells and the regulation of inflammation via the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA)-cAMP response element binding (CREB) signal pathway in NR8383 macrophages. In TGR5-knockdown H1299 cells, TCDCA significantly activated cAMP level via TGR5 receptor, indicating TCDCA can bind to TGR5; in NR8383 macrophages TCDCA increased cAMP content compared to treatment with the adenylate cyclase (AC) inhibitor SQ22536. Moreover, activated cAMP can significantly enhance gene expression and protein levels of its downstream proteins PKA and CREB compared with groups of inhibitors. Additionally, TCDCA decreased tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, IL-8 and IL-12 through nuclear factor kappa light chain enhancer of activated B cells (NF-κB) activity. PKA and CREB are primary regulators of anti-inflammatory and immune response. Our results thus demonstrate TCDCA plays an essential anti-inflammatory role via the signaling pathway of cAMP-PKA-CREB induced by TGR5 receptor.
Animals ; Cell Line ; Cyclic AMP/metabolism* ; Cyclic AMP Response Element-Binding Protein/metabolism* ; Cyclic AMP-Dependent Protein Kinases/metabolism* ; Cytokines/metabolism* ; Humans ; Inflammation ; Macrophages ; Rats ; Receptors, G-Protein-Coupled/metabolism* ; Signal Transduction/drug effects* ; Taurochenodeoxycholic Acid/pharmacology*

OBJECTIVE: To observe the direct intervention effects of electroacupuncture (EA) and non-steroid anti-inflammatory drugs (NSAIDs) on pain memory, and to explore their effects on cAMP/PKA/cAMP pathway in anterior cingulate gyrus (ACC). METHODS: Fifty clean healthy male SD rats were randomly divided into a control group, a model group, an indomethacin group, an EA group and a sham EA group, 10 rats in each group. Except the control group, the pain memory model was established in the remaining four groups by twice injection of carrageenan at foot; 0.1 mL of 2%λ-carrageenan was subcutaneously injected at the left foot of rats; 14 days later, when the pain threshold of rats of each group returned to the basic level, the second injection was performed with the same procedure. The rats in the EA group were treated with EA at bilateral "Zusanli" (ST 36) for 30 min; the rats in the indomethacin group was treated with indomethacin intragastric administration with the dose of 3 mg/kg; the rats in the sham EA group was treated with EA without electricity at the point 0.3 mm forward "Zusanli" (ST 36) with the depth of 2 mm for 30 min; the rats in the control group was not given any invention. All the above interventions were performed 5 h, 1 d, 2 d and 3 d after the second injection of 2% λ-carrageenan. The left-side paw withdrawal thresholds (PWT) were observed before the first injection, 4 h, 3 d, 5 d after the first injection, before the second injection and 4 h, 1 d, 2 d, 3 d after the second injection. Three days after the second injection, the number of positive cells of cAMP, p-PKA, p-CREB and the number of positive cells of protein co-expression in the right ACC brain area were detected by immunofluorescence, and the relative protein expression of p-PKA and p-CREB were detected by Western blot. RESULTS: Compared with the control group, the PWTs in the model group decreased significantly 4 h, 3 d and 5 d after the first injection and 1 d, 2 d and 3 d after the second injection (<0.05); compared with the control group, the positive expression of cAMP, p-PKA and p-CREB in the right ACC brain area in the model group increased significantly (<0.05), and the number of positive cells of the co-expression of cAMP/p-PKA and p-PKA/p-CREB also increased significantly (<0.05). Compared with the model group, indomethacin group and sham EA group, the PWTs in the EA group were increased significantly 1 d, 2 d and 3 d after the second injection (<0.05); compared with the model group, indomethacin group and sham EA group, the positive expression of p-PKA and p-CREB in the right ACC brain area in the EA group decreased significantly (<0.05), and the number of positive cells of co-expression of cAMP/p-PKA and p-PKA/p-CREB was decreased significantly (<0.05). Compared with the model group and sham EA group, the positive expression of cAMP in the right ACC brain area was decreased in the EA group (<0.05). CONCLUSION EA have a direct intervention effect on pain memory, which have significant advantage over NSAIDs in the treatment of chronic pain. The advantage effect of EA on pain memory may be related to the inhibition of cAMP/PKA/CREB pathway in ACC area.
Animals ; Anti-Inflammatory Agents, Non-Steroidal ; therapeutic use ; Cyclic AMP ; metabolism ; Cyclic AMP Response Element-Binding Protein ; metabolism ; Cyclic AMP-Dependent Protein Kinases ; metabolism ; Electroacupuncture ; Gyrus Cinguli ; metabolism ; Male ; Pain Threshold ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Signal Transduction

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

OBJECTIVEThe complex of the cyclic AMP receptor protein (CRP) and cAMP is an important transcriptional regulator of numerous genes in prokaryotes. The transport of mannitol through the phosphotransferase systems (PTS) is regulated by the CRP-cAMP complex. The aim of the study is to investigate how the CRP-cAMP complex acting on the mannitol PTS operon mtl of the Vibrio cholerae El Tor biotype.

METHODSThe crp mutant strain was generated by homologous recombination to assess the need of CRP to activate the mannitol PTS operon of V. cholerae El Tor. Electrophoretic mobility shift assays (EMSA) and the reporter plasmid pBBRlux were used to confirm the role that the CRP-cAMP complex playing on the mannitol PTS operon mtl.

RESULTSIn this study, we confirmed that CRP is strictly needed for the activation of the mtl operon. We further experimentally identified five CRP binding sites within the promoter region upstream of the mannitol PTS operon mtl of the Vibrio cholerae El Tor biotype and found that these sites display different affinities for CRP and provide different contributions to the activation of the operon.

CONCLUSIONThe five binding sites collectively confer the strong activation of mannitol transfer by CRP in V. cholerae, indicating an elaborate and subtle CRP activation mechanism.

Bacterial Proteins ; genetics ; Base Sequence ; Cyclic AMP ; metabolism ; Cyclic AMP Receptor Protein ; Gene Expression Regulation, Bacterial ; Mannitol ; Molecular Sequence Data ; Operon ; Phosphotransferases ; Vibrio cholerae