The RING domain of PIASy is involved in the suppression of bone morphogenetic protein-signaling pathway

Biochem Biophys Res Commun. 2004 Jun 18;319(1):275-82. doi: 10.1016/j.bbrc.2004.04.161.

Abstract

Bone morphogenetic proteins (BMPs) play central roles in differentiation, development, and physiologic tissue remodeling. Recently, we have demonstrated that a protein inhibitor of activated STAT, PIASy, suppresses TGF-beta signaling by interacting with Sma and MAD-related protein 3 (Smad3). In this study, we examined a PIASy-dependent inhibitory effect on BMP signaling. PIASy expression was induced by BMP-2 stimulation and suppressed BMP-2-dependent Smad activity in hepatoma cells. Furthermore, BMP-2-regulated Smads directly bound to PIASy. We also demonstrated that the RING domain of PIASy played an important role in PIASy-mediated suppression of Smad activity. We here provide evidence that the inhibitory action of PIASy on BMP-regulated Smad activity was due to direct physical interactions between Smads and PIASy through its RING domain.

MeSH terms

  • Blotting, Northern
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins / chemistry*
  • Bone Morphogenetic Proteins / metabolism
  • Carcinoma, Hepatocellular / metabolism
  • Carrier Proteins / chemistry*
  • Cell Line
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation
  • Humans
  • Immunoblotting
  • Intracellular Signaling Peptides and Proteins*
  • Luciferases / metabolism
  • Poly-ADP-Ribose Binding Proteins
  • Precipitin Tests
  • Protein Binding
  • Protein Inhibitors of Activated STAT
  • Protein Structure, Tertiary
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction*
  • Smad Proteins
  • Time Factors
  • Trans-Activators / metabolism
  • Transcription, Genetic
  • Transfection
  • Transforming Growth Factor beta*

Substances

  • BMP2 protein, human
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins
  • Carrier Proteins
  • DNA-Binding Proteins
  • Intracellular Signaling Peptides and Proteins
  • PIAS4 protein, human
  • Poly-ADP-Ribose Binding Proteins
  • Protein Inhibitors of Activated STAT
  • Smad Proteins
  • Trans-Activators
  • Transforming Growth Factor beta
  • Luciferases