SATB1 regulates SPARC expression in K562 cell line through binding to a specific sequence in the third intron

Biochem Biophys Res Commun. 2007 Apr 27;356(1):6-12. doi: 10.1016/j.bbrc.2007.01.201. Epub 2007 Feb 26.

Abstract

Special AT-rich binding protein 1 (SATB1), a cell type-specific nuclear matrix attachment region (MAR) DNA-binding protein, tethers to a specific DNA sequence and regulates gene expression through chromatin remodeling and HDAC (histone deacetylase complex) recruitment. In this study, a SATB1 eukaryotic expression plasmid was transfected into the human erythroleukemia K562 cell line and individual clones that stably over-expressed the SATB1 protein were isolated. Microarray analysis revealed that hundreds of genes were either up- or down-regulated in the SATB1 over-expressing K562 cell lines. One of these was the extra-cellular matrix glycoprotein, SPARC (human secreted protein acidic and rich in cysteine). siRNA knock-down of SATB1 also reduced SPARC expression, which was consistent with elevated SPARC levels in the SATB1 over-expressing cell line. Bioinformatics software Mat-inspector showed that a 17bp DNA sequence in the third intron of SPARC possessed a high potential for SATB1 binding; a finding confirmed by Chromatin immunoprecipitation (ChIP) with anti-SATB1 antibody. Our results show for the first time that forced-expression of SATB1 in K562 cells triggers SPARC up-regulation by binding to a 17bp DNA sequence in the third intron.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • Blotting, Western
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Chromatin Immunoprecipitation
  • Gene Expression Profiling
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Introns / genetics*
  • K562 Cells
  • Matrix Attachment Region Binding Proteins / genetics
  • Matrix Attachment Region Binding Proteins / metabolism
  • Matrix Attachment Region Binding Proteins / physiology*
  • Oligonucleotide Array Sequence Analysis
  • Protein Binding
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transfection

Substances

  • Carrier Proteins
  • Matrix Attachment Region Binding Proteins
  • SATB1 protein, human