Chemical proteomic map of dimethyl fumarate-sensitive cysteines in primary human T cells.
Dimethyl fumarate (DMF) is an electrophilic drug that is used to treat autoimmune conditions, including multiple sclerosis and psoriasis. The mechanism of action of DMF is unclear but may involve the covalent modification of proteins or DMF serving as a prodrug that is converted to monomethyl fumarate (MMF). We found that DMF, but not MMF, blocked the activation of primary human and mouse T cells. Using a quantitative, site-specific chemical proteomic platform, we determined the DMF sensitivity of >2400 cysteine residues in human T cells. Cysteines sensitive to DMF, but not MMF, were identified in several proteins with established biochemical or genetic links to T cell function, including protein kinase Cθ (PKCθ). DMF blocked the association of PKCθ with the costimulatory receptor CD28 by perturbing a CXXC motif in the C2 domain of this kinase. Mutation of these DMF-sensitive cysteines also impaired PKCθ-CD28 interactions and T cell activation, designating the C2 domain of PKCθ as a key functional, electrophile-sensing module important for T cell biology.
Department of Chemical Physiology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Megan M
MM
Blewett
Division of Cell Biology, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA 92037, USA.
Jiji
J
Xie
Department of Chemical Physiology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Balyn W
BW
Zaro
Department of Chemical Physiology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Keriann M
KM
Backus
Division of Cell Biology, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA 92037, USA.
Amnon
A
Altman
Department of Chemical Physiology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA. Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA. teijaro@scripps.edu cravatt@scripps.edu.
John R
JR
Teijaro
Department of Chemical Physiology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA. teijaro@scripps.edu cravatt@scripps.edu.
Benjamin F
BF
Cravatt
D000818:Animals; D018106:CD28 Antigens / Q000737:chemistry / Q000276:immunology; D003545:Cysteine / Q000737:chemistry / Q000276:immunology; D000069462:Dimethyl Fumarate / Q000737:chemistry*; D006801:Humans; D008213:Lymphocyte Activation / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D011493:Protein Kinase C / Q000737:chemistry / Q000276:immunology; D020543:Proteome / Q000737:chemistry* / Q000276:immunology; D040901:Proteomics; D013601:T-Lymphocytes / Q000737:chemistry* / Q000276:immunology
D018106:CD28 Antigens; D020543:Proteome; C081975:protein kinase C eta; D011493:Protein Kinase C; D000069462:Dimethyl Fumarate; D003545:Cysteine