title: Prediction and experimental validation of a putative non-consensus binding site for transcription factor STAT3 in serum amyloid A gene promoter.
abstract: We previously demonstrated that though the human SAA1 gene shows no typical STAT3 response element (STAT3-RE) in its promoter region, STAT3 and the nuclear factor (NF-κB) p65 first form a complex following interleukin IL-1 and IL-6 (IL-1+6) stimulation, after which STAT3 interacts with a region downstream of the NF-κB RE in the SAA1 promoter. In this study, we employed a computational approach based on indirect read outs of protein-DNA contacts to identify a set of candidates for non-consensus STAT3 transcription factor binding sites (TFBSs). The binding of STAT3 to one of the predicted non-consensus TFBSs was experimentally confirmed through a dual luciferase assay and DNA affinity chromatography. The present study defines a novel STAT3 non-consensus TFBS at nt -75/-66 downstream of the NF-κB RE in the SAA1 promoter region that is required for NF-κB p65 and STAT3 to activate SAA1 transcription in human HepG2 liver cells. Our analysis builds upon the current understanding of STAT3 function, suggesting a wider array of mechanisms of STAT3 function in inflammatory response, and provides a useful framework for investigating novel TF-target associations with potential therapeutic implications.
authors: Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors: Prabha
authors: P
authors: Tiwari
authors: Lokesh P
authors: LP
authors: Tripathi
authors: Teppei
authors: T
authors: Nishikawa-Matsumura
authors: Shandar
authors: S
authors: Ahmad
authors: Soken-Nakazawa J
authors: SN
authors: Song
authors: Tomoyasu
authors: T
authors: Isobe
authors: Kenji
authors: K
authors: Mizuguchi
authors: Kazuyuki
authors: K
authors: Yoshizaki
mesh_terms: D056945:Hep G2 Cells; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D020218:Response Elements / Q000502:physiology*; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D000685:Serum Amyloid A Protein / Q000096:biosynthesis* / Q000235:genetics; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology*
chemical_list: C508600:IL6 protein, human; D007375:Interleukin-1; D015850:Interleukin-6; C498143:RELA protein, human; C521404:SAA1 protein, human; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D000685:Serum Amyloid A Protein; D051996:Transcription Factor RelA