PuSH - Publication Server of Helmholtz Zentrum München

Eitelhuber, A.C. ; Warth, S.C. ; Schimmack, G. ; Düwel, M. ; Hadian, K. ; Demski, K. ; Beisker, W. ; Shinohara, H.* ; Kurosaki, T.* ; Heissmeyer, V. ; Krappmann, D.

Dephosphorylation of Carma1 by PP2A negatively regulates T-cell activation.

EMBO J. 30, 594-605 (2011)
DOI PMC
Open Access Gold as soon as Publ. Version/Full Text is submitted to ZB.
The Carma1-Bcl10-Malt1 (CBM) complex bridges T-cell receptor (TCR) signalling to the canonical IκB kinase (IKK)/NF-κB pathway. NF-κB activation is triggered by PKCθ-dependent phosphorylation of Carma1 after TCR/CD28 co-stimulation. PKCθ-phosphorylated Carma1 was suggested to function as a molecular scaffold that recruits preassembled Bcl10-Malt1 complexes to the membrane. We have identified the serine-threonine protein phosphatase PP2A regulatory subunit Aα (PPP2R1A) as a novel interaction partner of Carma1. PPP2R1A is associated with Carma1 in resting as well as activated T cells in the context of the active CBM complex. By siRNA-mediated knockdown and in vitro dephosphorylation, we demonstrate that PP2A removes PKCθ-dependent phosphorylation of Ser645 in Carma1, and show that maintenance of this phosphorylation is correlated with increased T-cell activation. As a result of PP2A inactivation, we find that enhanced Carma1 S645 phosphorylation augments CBM complex formation, NF-κB activation and IL-2 or IFN-γ production after stimulation of Jurkat T cells or murine Th1 cells. Thus, our data define PP2A-mediated dephosphorylation of Carma1 as a critical step to limit T-cell activation and effector cytokine production.
Altmetric
Additional Metrics?
[➜Log in]
Edit extra informations Login
Publication type Article: Journal article
Document type Scientific Article
Keywords Carma1; NF-κB,; P2A; T-cell activation
ISSN (print) / ISBN 0261-4189
e-ISSN 1460-2075
Journal EMBO Journal, The
Quellenangaben Volume: 30, Issue: 3, Pages: 594-605 Article Number: , Supplement: ,
Publisher Wiley
Publishing Place Heidelberg, Germany
Reviewing status Peer reviewed
Institute(s) Research Unit Signaling and Translation (SAT)
Institute of Molecular Immunology (IMI)
Institute of Molecular Toxicology and Pharmacology (TOX)
Research Unit Molecular Immune Regulation (AMIR)