Chemical proteomic map of dimethyl fumarate-sensitive cysteines in primary human T cells

Sci Signal. 2016 Sep 13;9(445):rs10. doi: 10.1126/scisignal.aaf7694.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD28 Antigens / chemistry
  • CD28 Antigens / immunology
  • Cysteine / chemistry
  • Cysteine / immunology
  • Dimethyl Fumarate / chemistry*
  • Humans
  • Lymphocyte Activation / physiology
  • Mice
  • Mice, Knockout
  • Protein Kinase C / chemistry
  • Protein Kinase C / immunology
  • Proteome / chemistry*
  • Proteome / immunology
  • Proteomics*
  • T-Lymphocytes / chemistry*
  • T-Lymphocytes / immunology


  • CD28 Antigens
  • Proteome
  • protein kinase C eta
  • Protein Kinase C
  • Dimethyl Fumarate
  • Cysteine