Identification of PGAM5 as a Mammalian Protein Histidine Phosphatase that Plays a Central Role to Negatively Regulate CD4(+) T Cells

Mol Cell. 2016 Aug 4;63(3):457-69. doi: 10.1016/j.molcel.2016.06.021. Epub 2016 Jul 21.


Whereas phosphorylation of serine, threonine, and tyrosine is exceedingly well characterized, the role of histidine phosphorylation in mammalian signaling is largely unexplored. Here we show that phosphoglycerate mutase family 5 (PGAM5) functions as a phosphohistidine phosphatase that specifically associates with and dephosphorylates the catalytic histidine on nucleoside diphosphate kinase B (NDPK-B). By dephosphorylating NDPK-B, PGAM5 negatively regulates CD4(+) T cells by inhibiting NDPK-B-mediated histidine phosphorylation and activation of the K(+) channel KCa3.1, which is required for TCR-stimulated Ca(2+) influx and cytokine production. Using recently developed monoclonal antibodies that specifically recognize phosphorylation of nitrogens at the N1 (1-pHis) or N3 (3-pHis) positions of the imidazole ring, we detect for the first time phosphoisoform-specific regulation of histidine-phosphorylated proteins in vivo, and we link these modifications to TCR signaling. These results represent an important step forward in studying the role of histidine phosphorylation in mammalian biology and disease.

Keywords: PGAM5; T cell activation; histidine phosphorylation; protein histidine phosphatases.

Publication types

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

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / enzymology*
  • CD4-Positive T-Lymphocytes / immunology
  • Calcium Signaling
  • Cytokines / metabolism
  • Genetic Predisposition to Disease
  • Graft vs Host Disease / enzymology
  • Graft vs Host Disease / genetics
  • Graft vs Host Disease / immunology
  • HEK293 Cells
  • Hematopoietic Stem Cell Transplantation / adverse effects
  • Histidine
  • Humans
  • Inflammation Mediators / metabolism
  • Intermediate-Conductance Calcium-Activated Potassium Channels / metabolism
  • Jurkat Cells
  • Lymphocyte Activation*
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism*
  • Nucleoside-Diphosphate Kinase / metabolism
  • Phenotype
  • Phosphoprotein Phosphatases / deficiency
  • Phosphoprotein Phosphatases / genetics
  • Phosphoprotein Phosphatases / metabolism*
  • Phosphorylation
  • RNA Interference
  • Receptors, Antigen, T-Cell / metabolism
  • Time Factors
  • Transfection


  • Cytokines
  • Inflammation Mediators
  • Intermediate-Conductance Calcium-Activated Potassium Channels
  • KCNN4 protein, human
  • Kcnn4 protein, mouse
  • Mitochondrial Proteins
  • Receptors, Antigen, T-Cell
  • Histidine
  • Nucleoside-Diphosphate Kinase
  • NDPK-B protein, human
  • PGAM5 protein, human
  • PGAM5 protein, mouse
  • Phosphoprotein Phosphatases