The phosphatase JKAP/DUSP22 inhibits T-cell receptor signalling and autoimmunity by inactivating Lck

Nat Commun. 2014 Apr 9;5:3618. doi: 10.1038/ncomms4618.


JNK pathway-associated phosphatase (JKAP, also known as DUSP22 or JSP-1) is a JNK activator. The in vivo role of JKAP in immune regulation remains unclear. Here we report that JKAP directly inactivates Lck by dephosphorylating tyrosine-394 residue during T-cell receptor (TCR) signalling. JKAP-knockout T cells display enhanced cell proliferation and cytokine production. JKAP-knockout mice show enhanced T-cell-mediated immune responses and are more susceptible to experimental autoimmune encephalomyelitis (EAE). In addition, the recipient mice that are adoptively transferred with JKAP-knockout T cells show exacerbated EAE symptoms. Aged JKAP-knockout mice spontaneously develop inflammation and autoimmunity. Thus, our results indicate that JKAP is an important phosphatase that inactivates Lck in the TCR signalling turn-off stage, leading to suppression of T-cell-mediated immunity and autoimmunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoimmunity / genetics
  • Autoimmunity / physiology*
  • Cell Line, Tumor
  • Densitometry
  • Dual-Specificity Phosphatases / genetics
  • Dual-Specificity Phosphatases / metabolism*
  • Encephalomyelitis, Autoimmune, Experimental / enzymology
  • Encephalomyelitis, Autoimmune, Experimental / genetics
  • Encephalomyelitis, Autoimmune, Experimental / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Immunoblotting
  • Immunoprecipitation
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microscopy, Confocal
  • Phosphoprotein Phosphatases / genetics
  • Phosphoprotein Phosphatases / metabolism*
  • Signal Transduction* / genetics
  • Signal Transduction* / physiology


  • JKAP protein, mouse
  • Phosphoprotein Phosphatases
  • Dual-Specificity Phosphatases
  • Dusp22 protein, mouse