Abstract
The angiotensin II peptide analog [Sar(1),Ile(4),Ile(8)]AngII (SII) is a biased AT(1A) receptor agonist that stimulates receptor phosphorylation, β-arrestin recruitment, receptor internalization, and β-arrestin-dependent ERK1/2 activation without activating heterotrimeric G-proteins. To determine the scope of G-protein-independent AT(1A) receptor signaling, we performed a gel-based phosphoproteomic analysis of AngII and SII-induced signaling in HEK cells stably expressing AT(1A) receptors. A total of 34 differentially phosphorylated proteins were detected, of which 16 were unique to SII and eight to AngII stimulation. MALDI-TOF/TOF mass fingerprinting was employed to identify 24 SII-sensitive phosphoprotein spots, of which three (two peptide inhibitors of protein phosphatase 2A (I1PP2A and I2PP2A) and prostaglandin E synthase 3 (PGES3)) were selected for validation and further study. We found that phosphorylation of I2PP2A was associated with rapid and transient inhibition of a β-arrestin 2-associated pool of protein phosphatase 2A, leading to activation of Akt and increased phosphorylation of glycogen synthase kinase 3β in an arrestin signalsome complex. SII-stimulated PGES3 phosphorylation coincided with an increase in β-arrestin 1-associated PGES3 and an arrestin-dependent increase in cyclooxygenase 1-dependent prostaglandin E(2) synthesis. These findings suggest that AT(1A) receptors regulate a robust G protein-independent signaling network that affects protein phosphorylation and autocrine/paracrine prostaglandin production and that these pathways can be selectively modulated by biased ligands that antagonize G protein activation.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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Angiotensin II / analogs & derivatives
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Angiotensin II / pharmacology*
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Arrestins / genetics
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Arrestins / metabolism
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Cyclooxygenase 1 / genetics
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Cyclooxygenase 1 / metabolism
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DNA-Binding Proteins
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Dinoprostone / biosynthesis
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Dinoprostone / genetics
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GTP-Binding Proteins / genetics
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GTP-Binding Proteins / metabolism*
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Glycogen Synthase Kinase 3 / genetics
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Glycogen Synthase Kinase 3 / metabolism
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Glycogen Synthase Kinase 3 beta
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HEK293 Cells
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Histone Chaperones / genetics
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Histone Chaperones / metabolism
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Humans
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Mitogen-Activated Protein Kinase 1 / genetics
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Mitogen-Activated Protein Kinase 1 / metabolism
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Mitogen-Activated Protein Kinase 3 / genetics
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Mitogen-Activated Protein Kinase 3 / metabolism
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Phosphorylation / drug effects
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Phosphorylation / physiology
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Protein Phosphatase 2 / genetics
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Protein Phosphatase 2 / metabolism
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Receptor, Angiotensin, Type 1 / genetics
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Receptor, Angiotensin, Type 1 / metabolism*
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Signal Transduction / drug effects*
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Signal Transduction / physiology
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Transcription Factors / genetics
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Transcription Factors / metabolism
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Vasoconstrictor Agents / pharmacology*
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beta-Arrestin 1
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beta-Arrestin 2
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beta-Arrestins
Substances
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ARRB1 protein, human
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ARRB2 protein, human
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Arrestins
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DNA-Binding Proteins
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Histone Chaperones
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Receptor, Angiotensin, Type 1
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SET protein, human
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Transcription Factors
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Vasoconstrictor Agents
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beta-Arrestin 1
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beta-Arrestin 2
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beta-Arrestins
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Angiotensin II
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Cyclooxygenase 1
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PTGS1 protein, human
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GSK3B protein, human
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Glycogen Synthase Kinase 3 beta
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MAPK1 protein, human
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinase 3
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Glycogen Synthase Kinase 3
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Protein Phosphatase 2
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GTP-Binding Proteins
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Dinoprostone