CD3/CD28 costimulation-induced NF-kappaB activation is mediated by recruitment of protein kinase C-theta, Bcl10, and IkappaB kinase beta to the immunological synapse through CARMA1.
CARMA1 (also known as CARD11) is a scaffold molecule and contains a caspase-recruitment domain (CARD) and a membrane-associated guanylate kinase-like (MAGUK) domain. It plays an essential role in mediating CD3/CD28 costimulation-induced NF-kappaB activation. However, the molecular mechanism by which CARMA1 mediates costimulatory signals remains to be determined. Here, we show that CARMA1 is constitutively associated with the cytoplasmic membrane. This membrane association is essential for the function of CARMA1, since a mutant of CARMA1, CARMA1(L808P), that is defective in the membrane association cannot rescue CD3/CD28 costimulation-induced NF-kappaB activation in JPM50.6 CARMA1-deficient T cells. Although CD3/CD28 costimulation effectively induces the formation of the immunological synapse in CARMA1-deficient T cells, the recruitment of protein kinase C-theta (PKC-theta), Bcl10, and IkappaB kinase beta (IKKbeta) into lipid rafts of the immunological synapse is defective. Moreover, expression of wild-type CARMA1, but not CARMA1(L808P), restores the recruitment of PKC-theta, Bcl10, and IKKbeta into lipid rafts in CARMA1-deficient T cells. Consistently, expression of a mutant CARMA1, CARMA1(DeltaCD), that cannot associate with Bcl10 failed to restore CD3/CD28 costimulation-induced NF-kappaB activation in JPM50.6 cells, whereas expression of Bcl10-CARMA(DeltaCD) fusion protein effectively restored this NF-kappaB activation. Together, these results indicate that CARMA1 mediates CD3/CD28 costimulation-induced NF-kappaB activation by recruiting downstream signaling components into the immunological synapse.
Wang
Donghai
D
Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, New York 14214, USA.
Matsumoto
Reiko
R
You
Yun
Y
Che
Tuanjie
T
Lin
Xue-Yan
XY
Gaffen
Sarah L
SL
Lin
Xin
X
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D000074018:B-Cell CLL-Lymphoma 10 Protein; D053468:CARD Signaling Adaptor Proteins; D018106:CD28 Antigens / Q000378:metabolism*; D017252:CD3 Complex / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D014644:Genetic Variation; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051550:I-kappa B Kinase; D007527:Isoenzymes / Q000378:metabolism; D019169:Jurkat Cells; D021962:Membrane Microdomains / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D000074121:Protein Kinase C-theta; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D000074018:B-Cell CLL-Lymphoma 10 Protein; C118591:BCL10 protein, human; D053468:CARD Signaling Adaptor Proteins; D018106:CD28 Antigens; D017252:CD3 Complex; D002352:Carrier Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; D016328:NF-kappa B; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; C076233:PRKCQ protein, human; D011493:Protein Kinase C; D000074121:Protein Kinase C-theta; C426242:CARD11 protein, human; D006162:Guanylate Cyclase