Diversity of cAMP-Dependent Protein Kinase Isoforms and Their Anchoring Proteins in Mouse Ventricular Tissue

Scholten, Arjen; Veen, Toon A.B. van; Vos, Marc A.; Heck, Albert J. R.

doi:10.1021/pr060601a

Cited by 49 publications

(49 citation statements)

References 70 publications

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“…D-AKAP1 (45), also called AKAP121 (9), and its shorter splice variant AKAP84 are mitochondrial proteins that are widely expressed in different tissues including heart ventricles (97). Recent functional studies performed in rat neonatal ventricular myocytes indicate that D-AKAP1 negatively regulates cardiomyocytes hypertrophy (1).…”

Section: Akaps and Cardiac Hypertrophymentioning

confidence: 99%

A-kinase anchoring proteins: scaffolding proteins in the heart

Diviani

Dodge‐Kafka

et al. 2011

American Journal of Physiology-Heart and Circulatory Physiology

101

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The pleiotropic cyclic nucleotide cAMP is the primary second messenger responsible for autonomic regulation of cardiac inotropy, chronotropy, and lusitropy. Under conditions of prolonged catecholaminergic stimulation, cAMP also contributes to the induction of both cardiac myocyte hypertrophy and apoptosis. The formation of localized, multiprotein complexes that contain different combinations of cAMP effectors and regulatory enzymes provides the architectural infrastructure for the specialization of the cAMP signaling network. Scaffolds that bind protein kinase A are called “A-kinase anchoring proteins” (AKAPs). In this review, we discuss recent advances in our understanding of how PKA is compartmentalized within the cardiac myocyte by AKAPs and how AKAP complexes modulate cardiac function in both health and disease.

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Section: Akaps and Cardiac Hypertrophymentioning

confidence: 99%

A-kinase anchoring proteins: scaffolding proteins in the heart

Diviani

Dodge‐Kafka

et al. 2011

American Journal of Physiology-Heart and Circulatory Physiology

101

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“…8 Cardiac myocytes express all four types of PKA isozymes, PKA-RI␣, PKA-RII␣, PKA-RI␤, and PKA-RII␤. 9 PKA isoforms show different subcellular localization, with PKA-RII being mainly associated with the particulate fraction of cell lysates whereas PKA-RI has been found preferentially in the cytosol. 10,11 PKA isoforms also show different biochemical properties.…”

mentioning

confidence: 99%

Protein Kinase A Type I and Type II Define Distinct Intracellular Signaling Compartments

Benedetto

Zoccarato

Lissandron

et al. 2008

Circulation Research

186

206

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Abstract-Protein kinase A (PKA) is a key regulatory enzyme that, on activation by cAMP, modulates a wide variety of cellular functions. PKA isoforms type I and type II possess different structural features and biochemical characteristics, resulting in nonredundant function. However, how different PKA isoforms expressed in the same cell manage to perform distinct functions on activation by the same soluble intracellular messenger, cAMP, remains to be established. Here, we provide a mechanism for the different function of PKA isoforms subsets in cardiac myocytes and demonstrate that PKA-RI and PKA-RII, by binding to AKAPs (A kinase anchoring proteins), are tethered to different subcellular locales, thus defining distinct intracellular signaling compartments. Within such compartments, PKA-RI and PKA-RII respond to distinct, spatially restricted cAMP signals generated in response to specific G protein-coupled receptor agonists and regulated by unique subsets of the cAMP degrading phosphodiesterases. Key Words: cAMP Ⅲ compartmentalization Ⅲ compartmentation Ⅲ adrenergic stimulation Ⅲ prostaglandin Ⅲ protein kinase A P rotein kinase A (PKA) is a key regulatory enzyme in the heart that is involved in the catecholamine-mediated control of excitation-contraction coupling, as well as in a myriad of other functions including activation of transcription factors and control of metabolic enzymes. The second messenger cAMP activates PKA by binding to the regulatory (R) subunits, causing release of the activated catalytic (C) subunits.The fact that, following cAMP-engagement, PKA mediates a plethora of cellular responses has raised the question of how specificity is maintained. In recent years, features of this pathway that contribute to specificity have been uncovered. 1 A key role is played by AKAPs (A kinase anchoring proteins), a family of proteins that act as molecular scaffolds to anchor PKA in the vicinity of specific substrate molecules, 2 thus focusing PKA activity toward relevant substrates.A second mechanism contributing to specificity revolves around the spatial control of the cAMP signal itself. Restriction of intracellular diffusion of cAMP has been shown by using a variety of approaches, [3][4][5] including direct imaging of gradients of cAMP in response to activation of various G protein-coupled receptors (GPCRs). 6 A key role in shaping cAMP intracellular pools is played by phosphodiesterases (PDEs), the enzymes that hydrolyze cAMP. 7 Indeed, individual PDE isoforms have been shown to be functionally coupled to specific GPCRs to degrade cAMP selectively in response to a given stimulus. 8 Cardiac myocytes express all four types of PKA isozymes, PKA-RI␣, PKA-RII␣, PKA-RI␤, and PKA-RII␤. 9 PKA isoforms show different subcellular localization, with PKA-RII being mainly associated with the particulate fraction of cell lysates whereas PKA-RI has been found preferentially in the cytosol. 10,11 PKA isoforms also show different biochemical properties. PKA-RI is more readily dissociated by cAMP than PKA-RII, 12,13 an...

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“…Recently, we introduced methodology to identify at a medium-large scale different cAMP/PKA-linked scaffolds in a qualitative way identifying several AKAPs present in heart tissue (17,21). For this, we applied specific enrichment of PKA⅐AKAP complexes using immobilized cAMP.…”

Section: Discussionmentioning

confidence: 99%

“…Tissue and Cell Lysate Preparation-Lysate and tissue preparation protocols were largely as described previously (17,21). Briefly, HEK293 cells (1.5 ϫ 10 6 cells/ml) were lysed by dounce homogenization and were left on ice for 10 min.…”

Section: Methodsmentioning

confidence: 99%

“…For control, beads blocked by ethanolamine were used in a parallel identical pulldown procedure. Prior to the pulldown assays, tissue and cell lysates were incubated with 10 mM ADP/GDP and incubated for 15 min at 4°C to reduce nonspecific binding, mainly contributed by ADP-and GDP-binding proteins (17,21). cAMP-agarose beads were added to the lysate in the volume ratio of 1:100 beads to lysate ratio.…”

Section: Methodsmentioning

confidence: 99%

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Selectivity in Enrichment of cAMP-dependent Protein Kinase Regulatory Subunits Type I and Type II and Their Interactors Using Modified cAMP Affinity Resins

Aye

Mohammed

Toorn

et al. 2009

Molecular & Cellular Proteomics

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cAMP regulates cellular functions primarily by activating PKA. The involvement of PKAs in various signaling pathways occurring simultaneously in different cellular compartments necessitates stringent spatial and temporal regulation. This specificity is largely achieved by binding of PKA to protein scaffolds, whereby a distinct group of proteins called A kinase anchoring proteins (AKAPs) play a dominant role. AKAPs are a diverse family of proteins that all bind via a small PKA binding domain to the regulatory subunits of PKA. The binding affinities between PKA and several AKAPs can be different for different isoforms of the regulatory subunits of PKA. Here we employ a combination of affinity chromatography and mass spectrometry-based quantitative proteomics to investigate specificity in PKA-AKAP interactions. Three different immobilized cAMP analogs were used to enrich for PKA and its interacting proteins from several systems; HEK293 and RCC10 cells and rat lung and testis tissues. Stable isotope labeling was used to confidently identify and differentially quantify target proteins and their preferential binding affinity for the three different cAMP analogs. We were able to enrich all four isoforms of the regulatory subunits of PKA and concomitantly identify more than 10 AKAPs. A selective enrichment of the PKA RI isoforms could be achieved; which allowed us to unravel which AKAPs bind preferentially to the RI or RII regulatory domains of PKA. Of the twelve AKAPs detected, seven preferentially bound to RII, whereas the remaining five displayed at least dual specificity with a potential preference for RI.

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Diversity of cAMP-Dependent Protein Kinase Isoforms and Their Anchoring Proteins in Mouse Ventricular Tissue

Cited by 49 publications

References 70 publications

A-kinase anchoring proteins: scaffolding proteins in the heart

A-kinase anchoring proteins: scaffolding proteins in the heart

Protein Kinase A Type I and Type II Define Distinct Intracellular Signaling Compartments

Selectivity in Enrichment of cAMP-dependent Protein Kinase Regulatory Subunits Type I and Type II and Their Interactors Using Modified cAMP Affinity Resins

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