Identification of a nuclear protein that promotes NF-kappaB activation

Biochem Biophys Res Commun. 2003 Oct 24;310(3):720-4. doi: 10.1016/j.bbrc.2003.09.074.

Abstract

Receptor-interacting protein (RIP) is a serine/threonine protein kinase that is critically involved in tumor necrosis factor receptor-1 (TNF-R1)-induced NF-kappaB activation. In a yeast two-hybrid screening for potential RIP-interacting proteins, we identified a novel protein designated as NKAP. Although NKAP interacts with RIP in yeast, NKAP does not interact with RIP in mammalian cells in co-immunoprecipitation experiments. When overexpressed in 293 cells, NKAP activated NF-kappaB in a dose-dependent manner. Moreover, down-regulation of NKAP by antisense RNA significantly inhibited TNF- and IL-1-induced NF-kappaB activation. Immunofluorescent staining indicated that NKAP was localized in the nucleus. Our findings suggest that NKAP is a novel nuclear regulator of TNF- and IL-1-induced NF-kappaB activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, CD / metabolism*
  • Blotting, Western
  • Cell Line
  • Cell Nucleus / metabolism*
  • Cloning, Molecular
  • Co-Repressor Proteins
  • DNA, Complementary / metabolism
  • Dose-Response Relationship, Drug
  • Down-Regulation
  • Enzyme Activation
  • Genes, Reporter
  • Humans
  • Luciferases / metabolism
  • Mice
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • NF-kappa B / metabolism*
  • Nuclear Proteins / chemistry*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Plasmids / metabolism
  • Precipitin Tests
  • Protein Binding
  • Proteins / physiology*
  • Receptor-Interacting Protein Serine-Threonine Kinases
  • Receptors, Tumor Necrosis Factor / metabolism*
  • Receptors, Tumor Necrosis Factor, Type I
  • Recombinant Proteins / metabolism
  • Repressor Proteins
  • Sequence Homology, Amino Acid
  • Transfection
  • Two-Hybrid System Techniques

Substances

  • Antigens, CD
  • Co-Repressor Proteins
  • DNA, Complementary
  • NF-kappa B
  • NKAP protein, human
  • Nuclear Proteins
  • Proteins
  • Receptors, Tumor Necrosis Factor
  • Receptors, Tumor Necrosis Factor, Type I
  • Recombinant Proteins
  • Repressor Proteins
  • Luciferases
  • RIPK1 protein, human
  • Receptor-Interacting Protein Serine-Threonine Kinases
  • Ripk1 protein, mouse