Quantitative phosphoproteomics dissection of 7TM receptor signaling using full and biased agonists
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Seven-transmembrane receptors (7TMRs) signal through the well described heterotrimeric G proteins, but can also activate G protein-independent signaling pathways of which the impact and complexity are less understood. The Angiotensin II type 1 receptor (AT1R) is a prototypical 7TMR and an important drug target in cardiovascular diseases. "Biased agonists", with intrinsic "functional selectivity", that simultaneously blocks Gaq protein activity, and activitates G protein independent pathways of the AT1R, confer important perspectives in treatment of cardiovascular diseases.n this study we performed a global quantitative phosphoproteomics analysis of the AT1R signaling network. We analyzed ligand-stimulated SILAC cells by high-resolution mass spectrometry (LTQ Orbitrap MS) and compared the phosphoproteomes of the AT1R agonist Angiotensin II and the biased agonist SII Angiotensin II, which only activates the Gaq protein-independent signaling.e quantified more than ten thousand phosphorylation sites of which 1183 were regulated by Angiotensin II or its analogue SII Angiotensin II. 36% of the AT1R regulated phosphorylations were regulated by SII Angiotensin II. Analysis of phosphorylation site patterns displays a striking distinction between protein kinases activated by Gaq protein-dependent and -independent mechanisms, and we now place protein kinase D as a key protein involved in both Gaq-dependent and independent AT1R signaling.his study provides substantial novel insight into Angiotensin II signal transduction and is the first study dissecting the differences between a full agonist and a biased agonist from a 7TMR on a systems-wide scale. Importantly, it reveals a previously unappreciated diversity and quantity of Gaq protein-independent signaling and uncovers novel signaling pathways. We foresee that the amount and diversity of G protein independent signaling may be more pronounced than previously recognized for other 7TMRs as well. Quantitative mass spectrometry is a promising tool for evaluation of the signaling properties of biased agonists to other receptors in the future.
Originalsprog | Engelsk |
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Tidsskrift | Molecular and Cellular Proteomics |
Vol/bind | 9 |
Udgave nummer | 7 |
Sider (fra-til) | 1540-53 |
Antal sider | 14 |
ISSN | 1535-9476 |
DOI | |
Status | Udgivet - jul. 2010 |
ID: 19160354