Mint represses transactivation of the type II collagen gene enhancer through interaction with alpha A-crystallin-binding protein 1

J Biol Chem. 2005 May 13;280(19):18710-6. doi: 10.1074/jbc.M500859200. Epub 2005 Mar 18.

Abstract

Collagen type II is an extracellular matrix protein important for cartilage and bone formation, and its expression is controlled by multiple cis- and trans-acting elements, including the zinc finger transcription factor alpha A-crystallin-binding protein 1 (CRYBP1). Here we show that MSX2-interacting nuclear target protein (MINT), a conserved transcriptional repressor, associates with CRYBP1 and negatively regulates the transactivation of the collagen type II gene (Col2a1) enhancer. We identified CRYBP1 as a binding partner of MINT by screening a mouse embryonic cDNA library using the yeast two-hybrid system. We demonstrated that the C terminus of MINT interacts with the C terminus of CRYBP1 using the mammalian cell two-hybrid assay, glutathione S-transferase pull-down, and co-immunoprecipitation analyses. Furthermore, MINT and CRYBP1 form a complex on the Col2a1 enhancer, as shown by chromatin immunoprecipitation and gel shift assays. In the presence of CRYBP1, overexpression of MINT or its C-terminal fragment in cells repressed a reporter construct driven by the Col2a1 enhancer elements. This transcription repression is dependent on histone deacetylase, the main co-repressor recruited by MINT. The present study shows that MINT is involved in CRYBP1-mediated Col2a1 gene repression and may play a role in regulation of cartilage development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone and Bones / metabolism
  • Cartilage / metabolism
  • Cell Line
  • Chromatin Immunoprecipitation
  • Collagen Type II / chemistry
  • Collagen Type II / genetics*
  • DNA, Complementary / metabolism
  • DNA-Binding Proteins / chemistry*
  • Enhancer Elements, Genetic*
  • Gene Expression Regulation
  • Gene Library
  • Genes, Reporter
  • Glutathione Transferase / metabolism
  • Histones / chemistry
  • Humans
  • Immunoprecipitation
  • Luciferases / metabolism
  • Mice
  • NIH 3T3 Cells
  • Nuclear Proteins / metabolism
  • Nuclear Proteins / physiology*
  • Plasmids / metabolism
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA-Binding Proteins
  • Transcription Factors / chemistry*
  • Transcriptional Activation*
  • Two-Hybrid System Techniques
  • Zinc Fingers
  • alpha-Crystallin A Chain / chemistry*

Substances

  • COL2A1 protein, human
  • Col2a1 protein, mouse
  • Collagen Type II
  • DNA, Complementary
  • DNA-Binding Proteins
  • Histones
  • Hivep1 protein, mouse
  • Nuclear Proteins
  • RNA-Binding Proteins
  • Spen protein, mouse
  • Transcription Factors
  • alpha-Crystallin A Chain
  • Luciferases
  • Glutathione Transferase