hTid-1, a human DnaJ protein, modulates the interferon signaling pathway

J Biol Chem. 2001 Dec 28;276(52):49034-42. doi: 10.1074/jbc.M103683200. Epub 2001 Oct 25.


The Jak family of protein-tyrosine kinases are crucial for the signaling of a large number of different polypeptide ligands, including the interferons, many cytokines, erythropoietin, and growth factors. Through their interaction with receptors, the Jaks initiate a signaling cascade resulting in the activation of gene transcription and ultimately a cellular response to various ligands. In addition to their role in cellular signaling, alteration of Jak activity has been implicated in several disease states. In identifying Jak2-interacting proteins with the yeast two-hybrid system, we cloned the human homologue of the Drosophila melanogaster tumor suppressor gene lethal () tumorous imaginal discs, which encodes the protein Tid56. Drosophila Tid56 and its human homologue hTid-1 represent members of the DnaJ family of molecular chaperones. The TID1 gene encodes two splice variants hTid-1(S) and hTid-1(L). We confirmed the interaction between Jak2 and hTid-1(S) or hTid-1(L) by immunoprecipitation from COS-1 cells expressing these proteins. The interaction between endogenous hTid-1 and Jak2 was shown in HEp2 cells. We further showed that hTid-1 interacts with the human interferon-gamma (Hu-IFN-gamma) receptor subunit IFN-gamma R2. In addition, using a chimeric construct where the extracellular domain of IFN-gamma R2 was fused to the kinase domain of Jak2, we showed that hTid-1 binds more efficiently to the chimera with an active kinase domain than to a similar construct with an inactive kinase domain. Additionally, the data demonstrate that hTid-1 isoforms as well as Jak2 interact with Hsp70/Hsc70 in vivo, and the interaction between Hsp70/Hsc70 and hTid-1 is reduced after IFN-gamma treatment. Furthermore, both hTid-1(S) and hTid-1(L) can modulate IFN-gamma-mediated transcriptional activity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • COS Cells
  • Cell Fractionation
  • Genes, Reporter
  • HSP40 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins / metabolism
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism*
  • Humans
  • Interferon-gamma / metabolism*
  • Janus Kinase 2
  • Models, Biological
  • Molecular Sequence Data
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein-Tyrosine Kinases / metabolism*
  • Proto-Oncogene Proteins*
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / physiology*
  • Transcription, Genetic
  • Tumor Cells, Cultured
  • Two-Hybrid System Techniques


  • DNAJA3 protein, human
  • HSP40 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins
  • Heat-Shock Proteins
  • Proto-Oncogene Proteins
  • Recombinant Fusion Proteins
  • Interferon-gamma
  • Protein-Tyrosine Kinases
  • JAK2 protein, human
  • Janus Kinase 2

Associated data

  • GENBANK/AF411044