title: SATB1 regulates SPARC expression in K562 cell line through binding to a specific sequence in the third intron.
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.
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical School of Shanghai Jiao Tong University, Shanghai 200025, PR China.
authors.forename: K
authors.initials: K
authors.lastname: Li
authors.forename: R
authors.initials: R
authors.lastname: Cai
authors.forename: B B
authors.initials: BB
authors.lastname: Dai
authors.forename: X Q
authors.initials: XQ
authors.lastname: Zhang
authors.forename: H J
authors.initials: HJ
authors.lastname: Wang
authors.forename: S F
authors.initials: SF
authors.lastname: Ge
authors.forename: W R
authors.initials: WR
authors.lastname: Xu
authors.forename: J
authors.initials: J
authors.lastname: Lu
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007438:Introns / Q000235:genetics*; D020014:K562 Cells; D036961:Matrix Attachment Region Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D011485:Protein Binding; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: D002352:Carrier Proteins; D036961:Matrix Attachment Region Binding Proteins; C076189:SATB1 protein, human