Dataset Information

"cAMP sponge": a buffer for cyclic adenosine 3', 5'-monophosphate.

ABSTRACT:

Background

While intracellular buffers are widely used to study calcium signaling, no such tool exists for the other major second messenger, cyclic AMP (cAMP).

Methods/principal findings

Here we describe a genetically encoded buffer for cAMP based on the high-affinity cAMP-binding carboxy-terminus of the regulatory subunit RIbeta of protein kinase A (PKA). Addition of targeting sequences permitted localization of this fragment to the extra-nuclear compartment, while tagging with mCherry allowed quantification of its expression at the single cell level. This construct (named "cAMP sponge") was shown to selectively bind cAMP in vitro. Its expression significantly suppressed agonist-induced cAMP signals and the downstream activation of PKA within the cytosol as measured by FRET-based sensors in single living cells. Point mutations in the cAMP-binding domains of the construct rendered the chimera unable to bind cAMP in vitro or in situ. Cyclic AMP sponge was fruitfully applied to examine feedback regulation of gap junction-mediated transfer of cAMP in epithelial cell couplets.

Conclusions

This newest member of the cAMP toolbox has the potential to reveal unique biological functions of cAMP, including insight into the functional significance of compartmentalized signaling events.

SUBMITTER: Lefkimmiatis K

PROVIDER: S-EPMC2766031 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature

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Publications

"cAMP sponge": a buffer for cyclic adenosine 3', 5'-monophosphate.

Lefkimmiatis Konstantinos K Moyer Mary Pat MP Curci Silvana S Hofer Aldebaran M AM

PloS one 20091103 11

<h4>Background</h4>While intracellular buffers are widely used to study calcium signaling, no such tool exists for the other major second messenger, cyclic AMP (cAMP).<h4>Methods/principal findings</h4>Here we describe a genetically encoded buffer for cAMP based on the high-affinity cAMP-binding carboxy-terminus of the regulatory subunit RIbeta of protein kinase A (PKA). Addition of targeting sequences permitted localization of this fragment to the extra-nuclear compartment, while tagging with m ...[more]

PMID: 19888343

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Project description:BackgroundThe cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) signaling pathway is closely associated with myocardial infarction (MI). Cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) is a key component of this pathway; however, there is currently a lack of clinical evidence linking plasma cGAMP levels to MI.MethodsThis study utilized clinical data from 270 patients diagnosed with coronary heart disease (CHD) at the Second Xiangya Hospital of Central South University. The outcomes included ST-segment elevation and non-ST-segment elevation MI. Univariate and multivariate logistic regression models were used to explore the relationships between plasma cGAMP levels and MI, while restricted cubic spline (RCS) using logistic regression to explore the dose-response relationship.ResultsAmong the 270 patients, the mean plasma cGAMP level was 1352.58 ± 106.02 ng/L and 89 (32.96%) patients were diagnosed with MI. The RCS curves indicated a U-shape association between the cGAMP levels and MI; the risk of MI was negatively correlated with the cGAMP until it hit bottoms at 1352 ng/L. When the cGAMP level exceeded 1352 ng/L, the risk of MI increased significantly (adjusted OR, 1.02; 95% CI: 1.01-1.03). When considering cGAMP as a categorical variable, patients in Tertile 1 and Tertile 3 had a 167% (adjusted OR: 2.67, 95% CI: 1.23-5.78) and 155% (adjusted OR: 2.55, 95% CI: 1.17-5.55) higher risk of MI compared to those in Tertile 2, respectively. These results were consistent across subgroup analyses, notably, a significant interaction by age category was observed in patients with cGAMP ≥ 1352 ng/L, where the positive association was pronounced in the elderly.ConclusionsA U-shaped association exists between cGAMP and MI in the CHD population, with a cutoff point at the cGAMP of 1352 ng/L. Both excessively high and low cGAMP levels are associated with an increased risk of MI, particularly among the elderly with cGAMP ≥ 1352 ng/L. This is the first clinical evidence of the cGAS-cGAMP-STING pathway in metabolic cardiovascular diseases.ClinicaltrialsGov identifierNCT03363035 (Registration date: 2018-01-15).

Dataset Information

"cAMP sponge": a buffer for cyclic adenosine 3', 5'-monophosphate.

Background

Methods/principal findings

Conclusions

Publications

"cAMP sponge": a buffer for cyclic adenosine 3', 5'-monophosphate.

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