Catalytic subunits of the phosphatase calcineurin interact with NF-κB-inducing kinase (NIK) and attenuate NIK-dependent gene expression

Sci Rep. 2015 Jun 1;5:10758. doi: 10.1038/srep10758.

Abstract

Nuclear factor (NF)-κB-inducing kinase (NIK) is a serine/threonine kinase that activates NF-κB pathways, thereby regulating a wide variety of immune systems. Aberrant NIK activation causes tumor malignancy, suggesting a requirement for precise regulation of NIK activity. To explore novel interacting proteins of NIK, we performed in vitro virus screening and identified the catalytic subunit Aα isoform of serine/threonine phosphatase calcineurin (CnAα) as a novel NIK-interacting protein. The interaction of NIK with CnAα in living cells was confirmed by co-immunoprecipitation. Calcineurin catalytic subunit Aβ isoform (CnAβ) also bound to NIK. Experiments using domain deletion mutants suggested that CnAα and CnAβ interact with both the kinase domain and C-terminal region of NIK. Moreover, the phosphatase domain of CnAα is responsible for the interaction with NIK. Intriguingly, we found that TRAF3, a critical regulator of NIK activity, also binds to CnAα and CnAβ. Depletion of CnAα and CnAβ significantly enhanced lymphotoxin-β receptor (LtβR)-mediated expression of the NIK-dependent gene Spi-B and activation of RelA and RelB, suggesting that CnAα and CnAβ attenuate NF-κB activation mediated by LtβR-NIK signaling. Overall, these findings suggest a possible role of CnAα and CnAβ in modifying NIK functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcineurin / metabolism*
  • Catalytic Domain
  • Cell Line / metabolism
  • Cytokine TWEAK
  • Gene Expression Regulation*
  • Humans
  • Isoenzymes
  • Lymphotoxin beta Receptor / metabolism
  • Mice
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Transport
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins c-ets / genetics
  • Signal Transduction
  • TNF Receptor-Associated Factor 3 / metabolism
  • Transcription Factor RelA / metabolism
  • Transcription Factor RelB / metabolism
  • Transcription Factors / genetics
  • Tumor Necrosis Factors / metabolism

Substances

  • Cytokine TWEAK
  • Isoenzymes
  • Lymphotoxin beta Receptor
  • Proto-Oncogene Proteins c-ets
  • Spi-B protein, mouse
  • TNF Receptor-Associated Factor 3
  • Tnfsf12 protein, mouse
  • Transcription Factor RelA
  • Transcription Factors
  • Tumor Necrosis Factors
  • Transcription Factor RelB
  • Protein-Serine-Threonine Kinases
  • NF-kappa B kinase
  • Calcineurin