CARMA3 deficiency abrogates G protein-coupled receptor-induced NF-{kappa}B activation.
G protein-coupled receptors (GPCRs) play pivotal roles in regulating various cellular functions. Although many GPCRs induce NF-kappaB activation, the molecular mechanism of GPCR-induced NF-kappaB activation remains largely unknown. CARMA3 (CARD and MAGUK domain-containing protein 3) is a scaffold molecule with unknown biological functions. By generating CARMA3 knockout mice using the gene targeting approach, here we show CARMA3 is required for GPCR-induced NF-kappaB activation. Mechanistically, we found that CARMA3 deficiency impairs GPCR-induced IkappaB kinase (IKK) activation, although it does not affect GPCR-induced IKKalpha/beta phosphorylation, indicating that inducible phosphorylation of IKKalpha/beta alone is not sufficient to induce its kinase activity. We also found that CARMA3 is physically associated with NEMO/IKKgamma, and induces polyubiquitination of an unknown protein(s) that associates with NEMO, likely by linking NEMO to TRAF6. Consistently, we found TRAF6 deficiency also abrogates GPCR-induced NF-kappaB activation. Together, our results provide the genetic evidence that CARMA3 is required for GPCR-induced NF-kappaB activation.
Grabiner
Brian C
BC
Department of Molecular and Cellular Oncology, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
Blonska
Marzenna
M
Lin
Pei-Chun
PC
You
Yun
Y
Wang
Donghai
D
Sun
Jiyuan
J
Darnay
Bryant G
BG
Dong
Chen
C
Lin
Xin
X
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D000074018:B-Cell CLL-Lymphoma 10 Protein; D053468:CARD Signaling Adaptor Proteins / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology; D005260:Female; D005347:Fibroblasts; D051550:I-kappa B Kinase / Q000378:metabolism; D008246:Lysophospholipids / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D016328:NF-kappa B / Q000378:metabolism*; D010766:Phosphorylation; D011247:Pregnancy; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D015398:Signal Transduction; D048029:TNF Receptor-Associated Factor 6 / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D000074018:B-Cell CLL-Lymphoma 10 Protein; C488088:Bcl10 protein, mouse; D053468:CARD Signaling Adaptor Proteins; C498975:Card10 protein, mouse; D008246:Lysophospholipids; D016328:NF-kappa B; D043562:Receptors, G-Protein-Coupled; D048029:TNF Receptor-Associated Factor 6; C496564:Chuk protein, mouse; D051550:I-kappa B Kinase; C032881:lysophosphatidic acid