Phosphorylation of Carma1, but not Bcl10, by Akt regulates TCR/CD28-mediated NF-κB induction and cytokine production

Jing Cheng; Kristia S Hamilton; Lawrence P Kane

doi:10.1016/j.molimm.2014.01.011

Phosphorylation of Carma1, but not Bcl10, by Akt regulates TCR/CD28-mediated NF-κB induction and cytokine production

Mol Immunol. 2014 May;59(1):110-6. doi: 10.1016/j.molimm.2014.01.011. Epub 2014 Feb 16.

Authors

Jing Cheng¹, Kristia S Hamilton², Lawrence P Kane³

Affiliations

¹ University of Pittsburgh, Department of Immunology, BST E-1056, 200 Lothrop Street, Pittsburgh, PA 15261, United States.
² University of Pittsburgh, Department of Immunology, BST E-1056, 200 Lothrop Street, Pittsburgh, PA 15261, United States; Graduate Program in Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, United States.
³ University of Pittsburgh, Department of Immunology, BST E-1056, 200 Lothrop Street, Pittsburgh, PA 15261, United States. Electronic address: lkane@pitt.edu.

Abstract

Previous studies from our group and others have shown that the Akt kinase can contribute to induction of NF-κB by antigen receptor signaling. However, the direct targets of Akt in this pathway are not known. Here we show that Akt-mediated NF-κB activation is mediated at least in part through direct phosphorylation of the adaptor protein Carma1, which we previously demonstrated could interact with Akt in a TCR ligation-dependent manner. The putative Akt phosphorylation sites in Carma1 are distinct from known PKC consensus sites. Mutation of S551, S637 and S645 in Carma1 to non-phosphorylatable residues decreased phosphorylation of GST-Carma1-linker construct by Akt in vitro. In addition, Carma1 S637A/S645A mutants were significantly impaired in their ability to restore TCR-mediated NF-κB activation and IL-2 expression in Carma1-deficient T cells. Thus, our data reveal Carma1 as a novel target for Akt phosphorylation and suggest that Akt-mediated phosphorylation of Carma1 is an additional regulatory mechanism tuning the NF-κB response downstream of antigen receptor and co-stimulatory signaling.

Keywords: Akt; NF-κB; Phosphorylation; Signal transduction; T cells.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Adaptor Proteins, Signal Transducing / immunology
Adaptor Proteins, Signal Transducing / metabolism
Amino Acid Sequence
B-Cell CLL-Lymphoma 10 Protein
Blotting, Western
CARD Signaling Adaptor Proteins / genetics
CARD Signaling Adaptor Proteins / immunology*
CARD Signaling Adaptor Proteins / metabolism
CD28 Antigens / immunology*
CD28 Antigens / metabolism
CD3 Complex / immunology
CD3 Complex / metabolism
Cell Line, Tumor
Cytokines / immunology*
Cytokines / metabolism
Guanylate Cyclase / genetics
Guanylate Cyclase / immunology*
Guanylate Cyclase / metabolism
HEK293 Cells
Humans
Interleukin-2 / immunology
Interleukin-2 / metabolism
Jurkat Cells
Molecular Sequence Data
Mutation
NF-kappa B / immunology*
NF-kappa B / metabolism
Phosphorylation / immunology
Proto-Oncogene Proteins c-akt / genetics
Proto-Oncogene Proteins c-akt / immunology*
Proto-Oncogene Proteins c-akt / metabolism
RNA Interference
Receptors, Antigen, T-Cell / immunology
Receptors, Antigen, T-Cell / metabolism

Substances

Adaptor Proteins, Signal Transducing
B-Cell CLL-Lymphoma 10 Protein
BCL10 protein, human
CARD Signaling Adaptor Proteins
CD28 Antigens
CD3 Complex
Cytokines
Interleukin-2
NF-kappa B
Receptors, Antigen, T-Cell
Proto-Oncogene Proteins c-akt
CARD11 protein, human
Guanylate Cyclase

Abstract

Publication types

MeSH terms

Substances

Grants and funding