AGAP1, a Novel Binding Partner of Nitric Oxide-sensitive Guanylyl Cyclase

Meurer, Sabine; Pioch, Sylke; Wagner, Kristina; Müller‐Esterl, Werner; Gross, Steffen

doi:10.1074/jbc.m410565200

Cited by 48 publications

(37 citation statements)

References 45 publications

(52 reference statements)

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“…blood vessels. 24 It will be intriguing to test for the differential expression of ␣ 1 versus C-␣ 1 under pathological conditions. Finally, we have identified CHIP as a likely candidate for an E3 ligase mediating sGC ubiquitination.…”

Section: Discussionmentioning

confidence: 99%

“…Under these less stringent conditions, the holoenzyme was retained in the immunoprecipitate using antibodies to ␣ 1 or ␤ 1, as evidenced by SDS-PAGE and Western blotting (WB). 24 To prepare total cell lysates, cells from a 60 mm dish were lysed in 0.5 mL sample buffer, sonicated and heated (10 minutes, 95°C). Before loading to the gel, samples were centrifuged (15,000g, 5 minutes).…”

Section: Aortic Cgmpmentioning

confidence: 99%

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Nitric Oxide–Independent Vasodilator Rescues Heme-Oxidized Soluble Guanylate Cyclase From Proteasomal Degradation

Meurer

Pioch

Pabst

et al. 2009

Circulation Research

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Abstract-Nitric oxide (NO) is an essential vasodilator. In vascular diseases, oxidative stress attenuates NO signaling by both chemical scavenging of free NO and oxidation and downregulation of its major intracellular receptor, the ␣␤ heterodimeric heme-containing soluble guanylate cyclase (sGC). Oxidation can also induce loss of the heme of sGC, as well as the responsiveness of sGC to NO. sGC activators such as BAY 58-2667 bind to oxidized/heme-free sGC and reactivate the enzyme to exert disease-specific vasodilation. Here, we show that oxidation-induced downregulation of sGC protein extends to isolated blood vessels. Mechanistically, degradation was triggered through sGC ubiquitination and proteasomal degradation. The heme-binding site ligand BAY 58-2667 prevented sGC ubiquitination and stabilized both ␣ and ␤ subunits. Collectively, our data establish oxidation-ubiquitination of sGC as a modulator of NO/cGMP signaling and point to a new mechanism of action for sGC activating vasodilators by stabilizing their receptor, oxidized/heme-free sGC. O ne major risk factor for the development of cardiovascular diseases, such as coronary heart disease, stroke, and myocardial infarction, is an imbalance of the production and elimination of reactive oxygen species, also termed as oxidative stress. [1][2][3] As a consequence, the nitric oxide (NO)/ cGMP signaling cascade is impaired, eg, through the excessive production of superoxide, which reacts with NO in a diffusion-limited reaction, yielding peroxynitrite. 4 The biological impact of NO scavenging is further aggravated by the progressive inhibition and downregulation of the NO receptor soluble guanylate cyclase (sGC). [5][6][7][8][9] Circumstantial evidence has implicated proteasomal pathways in this downregulation of sGC. 10 -12 Conversely, a novel class of sGC activators, represented by BAY 58-2667, are potentiated under oxidative stress conditions and represent thus an entirely new diseasespecific vasodilator class. 13 sGC is a heterodimer consisting of an ␣ and a Fe 2ϩ /hemecontaining ␤ subunit that complexes NO with high affinity and specificity. 14 Binding of NO to the Fe 2ϩ /heme results in allosteric activation of the enzyme and enhanced conversion of GTP into the vasorelaxant and antiproliferative second messenger cGMP. 14,15 In vitro experiments have demonstrated that oxidation of sGC heme to its ferric (Fe 3ϩ ) form by the sGC inhibitor 1H-[1,2,4]-oxadiazolo [3,4-a]quinoxalin-1-one (ODQ) attenuates NO-mediated cGMP production, suggesting that the ferro (Fe 2ϩ ) form of sGC is crucial for activation by NO. 16 -18 In addition, studies with primary endothelial and smooth muscle cells have revealed that, within 24 hours, ODQ causes a dramatic decrease in sGC protein levels. 13 Similar results were obtained with other oxidizing compounds such as methylene blue or the peroxynitrite donor 1,3-morpholino-sydnonimine hydrochloride (SIN-1), indicating that oxidative stress triggers downregulation of sGC protein levels. 13 At present, the molecular mechanisms under...

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Section: Discussionmentioning

confidence: 99%

Section: Aortic Cgmpmentioning

confidence: 99%

Nitric Oxide–Independent Vasodilator Rescues Heme-Oxidized Soluble Guanylate Cyclase From Proteasomal Degradation

Meurer

Pioch

Pabst

et al. 2009

Circulation Research

Self Cite

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“…of them is also a chaperonin (45) that participates with Hsp70 in protein folding, and the other one is AGAP1 (46), a member of the Arf-GAP family known to be involved in cytoskeleton organization.…”

Section: Figmentioning

confidence: 99%

Characterization of a Novel Type of Endogenous Activator of Soluble Guanylyl Cyclase

Balashova

Chang

Lamothe

et al. 2005

Journal of Biological Chemistry

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Nitric oxide (NO) remains the only firmly established endogenous modulator of soluble guanylyl cyclase (sGC) activity, but physiological, structural, and biochemical evidence now suggests that in vivo regulation of sGC involves direct interaction with other factors. We searched for such endogenous modulators in human umbilical vein endothelial cells and COS-7 cells. The cytosolic fraction of both cell types stimulated the activity of semipurified sGC severalfold in the absence or presence of a saturating concentration of NO. The cytosolic factor was sensitive to proteinase K and destroyed by boiling, suggesting that it contains a protein component. Size exclusion chromatography revealed peaks of activity between 40 and 70 kDa. The sGC-activating effect was further purified by ion exchange chromatography. In the presence of the benzylindazole YC-1 or NO, the partially purified factor synergistically activated sGC, suggesting that this factor had a mode of activation different from that of YC-1 or NO. Four candidate activators were identified from the final purification step by matrix-assisted laser desorption ionization mass spectrometry analysis. Using an sGC affinity matrix, one of them, the molecular chaperone Hsp70, was shown to directly interact with sGC. This interaction was further confirmed by co-immunoprecipitation in lung tissues and by co-localization in smooth muscle cells. sGC and Hsp70 co-localized at the plasma membrane, supporting the idea that sGC can be translocated to the membrane. Hsp70 co-purifies with the sGC-activating effect, and immunodepletion of Hsp70 from COS-7 cytosol coincided with a marked attenuation of the sGC-activating effect, yet the effect was not rescued by the addition of pure Hsp70. Thus, Hsp70 is a novel sGC-interacting protein that is responsible for the sGC-activating effect, probably in association with other factors or after covalent modification.

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“…In addition, centaurin-␥3 contains PH, Arf GAP, and ankyrin repeat domains, which are absent in CRAG. Centaurin-␥2/AGAP1, which bears a close resemblance to centaurin-␥3, also possesses a short splicing variant similar to CRAG (13,14). A luciferase assay was performed on Neuro2A cells transfected with HA-tagged CRAG (HA-CRAG) or indicated plasmids and a reporter gene containing an AP-1 site (pAP-1-Luc).…”

Section: Resultsmentioning

confidence: 99%

CRMP5-associated GTPase (CRAG) Protein Protects Neuronal Cells against Cytotoxicity of Expanded Polyglutamine Protein Partially via c-Fos-dependent Activator Protein-1 Activation

Nagashima

Fukuda

Kubota

et al. 2011

Journal of Biological Chemistry

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Background: CRAG expression in the Purkinje cells of mice expressing polyQ resulted in clearance of the polyQ and rescue from ataxia. Results: CRAG induces transcriptional activation of c-Fos-dependent AP-1 via SRF. Conclusion: CRAG enhances the cell survival signal against the cytotoxicity of polyQ partially via c-Fos-dependent AP-1 activation. Significance: Our findings extend the possible use of targeted delivery of CRAG as a gene therapy for polyglutamine diseases.

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AGAP1, a Novel Binding Partner of Nitric Oxide-sensitive Guanylyl Cyclase

Cited by 48 publications

References 45 publications

Nitric Oxide–Independent Vasodilator Rescues Heme-Oxidized Soluble Guanylate Cyclase From Proteasomal Degradation

Nitric Oxide–Independent Vasodilator Rescues Heme-Oxidized Soluble Guanylate Cyclase From Proteasomal Degradation

Characterization of a Novel Type of Endogenous Activator of Soluble Guanylyl Cyclase

CRMP5-associated GTPase (CRAG) Protein Protects Neuronal Cells against Cytotoxicity of Expanded Polyglutamine Protein Partially via c-Fos-dependent Activator Protein-1 Activation

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