title: Identification of beta-arrestin2 as a G protein-coupled receptor-stimulated regulator of NF-kappaB pathways.
abstract: Norepinephrine released by the sympathetic nerve terminals regulates the immune system primarily via its stimulation of beta(2)-adrenergic receptor (beta(2)AR), but the underlying molecular mechanisms remain to be elicited. Beta(2)AR, a well-studied G protein-coupled receptor (GPCR), is functionally regulated by beta-arrestin2, which not only causes receptor desensitization and internalization but also serves as a signaling molecule in GPCR signal transduction. Here we show that beta-arrestin2 directly interacts with IkappaBalpha (inhibitor of NF-kappaB, the key molecule in innate and adaptive immunity) and thus prevents the phosphorylation and degradation of IkappaBalpha. Consequently, beta-arrestin2 effectively modulates activation of NF-kappaB and expression of NF-kappaB target genes. Moreover, stimulation of beta(2)AR significantly enhances beta-arrestin2-IkappaBalpha interaction and greatly promotes beta-arrestin2 stabilization of IkappaBalpha, indicating that beta-arrestin2 mediates a crosstalk between beta(2)AR and NF-kappaB signaling pathways. Taken together, the current study may present a novel mechanism for regulation of the immune system by the sympathetic nervous system.
authors.affiliation: Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Gao
authors.forename: Yue
authors.initials: Y
authors.lastname: Sun
authors.forename: Yalan
authors.initials: Y
authors.lastname: Wu
authors.forename: Bing
authors.initials: B
authors.lastname: Luan
authors.forename: Yaya
authors.initials: Y
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Qu
authors.forename: Gang
authors.initials: G
authors.lastname: Pei
mesh_terms: D019390:Arrestins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D005786:Gene Expression Regulation / Q000235:genetics; D006801:Humans; D020672:I-kappa B Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D015213:Neuroimmunomodulation / Q000235:genetics; D010766:Phosphorylation; D017434:Protein Structure, Tertiary / Q000235:genetics; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D013564:Sympathetic Nervous System / Q000502:physiology; D000071557:beta-Arrestins
chemical_list: D019390:Arrestins; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D018343:Receptors, Adrenergic, beta-2; D043562:Receptors, G-Protein-Coupled; D000071557:beta-Arrestins; D000072000:NF-KappaB Inhibitor alpha