Heterologous down-regulation of angiotensin type 1 receptors by purinergic P2Y2 receptor stimulation through S-nitrosylation of NF-κB
Abstract
Cross-talk between G protein-coupled receptor (GPCR) signaling pathways serves to fine tune cellular responsiveness by neurohumoral factors. Accumulating evidence has implicated nitric oxide (NO)-based signaling downstream of GPCRs, but the molecular details are unknown. Here, we show that adenosine triphosphate (ATP) decreases angiotensin type 1 receptor (AT1R) density through NO-mediated S-nitrosylation of nuclear factor κB (NF-κB) in rat cardiac fibroblasts. Stimulation of purinergic P2Y2 receptor by ATP increased expression of inducible NO synthase (iNOS) through activation of nuclear factor of activated T cells, NFATc1 and NFATc3. The ATP-induced iNOS interacted with p65 subunit of NF-κB in the cytosol through flavin-binding domain, which was indispensable for the locally generated NO-mediated S-nitrosylation of p65 at Cys38. β-Arrestins anchored the formation of p65/IκBα/β-arrestins/iNOS quaternary complex. The S-nitrosylated p65 resulted in decreases in NF-κB transcriptional activity and AT1R density. In pressure-overloaded mouse hearts, ATP released from cardiomyocytes led to decrease in AT1R density through iNOS-mediated S-nitrosylation of p65. These results show a unique regulatory mechanism of heterologous regulation of GPCRs in which cysteine modification of transcriptional factor rather than protein phosphorylation plays essential roles.
- Publication:
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Proceedings of the National Academy of Science
- Pub Date:
- April 2011
- DOI:
- 10.1073/pnas.1017640108
- Bibcode:
- 2011PNAS..108.6662N