Characterization of binding between SF-1 and Sp1: predominant interaction of SF-1 with the N-terminal region of Sp1.
The transcription factor specificity protein 1 (Sp1) binds to GC boxes and interacts with many transcription factors to regulate gene expression. Steroidogenic factor-1 (SF-1) is an orphan nuclear receptor and plays a major role in regulation of the human steroidogenic acute regulatory (StAR) gene. We demonstrated that there is interaction between SF-1 and Sp1 on the human StAR promoter. In the present study, we examined the mechanism of the interaction between Sp1 and SF-1 on the human StAR gene promoter. Results of glutathione S-transferase (GST) pull-down assays and a mammalian two-hybrid assay showed that SF-1 interacted with Sp1 through the N-terminal domains of Sp1. Results of electrophoretic mobility shift assays using nuclear extracts showed that Sp1 is associated with SF-1-DNA complex formation. The density of SF-1-DNA complex was much greater when recombinant Sp1 was added to the incubation mixture. These results suggest that Sp1 interacts with SF-1 and that Sp1 enhances SF-1-DNA complex formation to regulate human StAR transcription.
Sugawara
T
T
Department of Biochemistry, Hokkaido University, Graduate School of Medicine, Sapporo, Japan. terusuga@med.hokudai.ac.jp
Nomura
E
E
Nakajima
A
A
Sakuragi
N
N
D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D051717:Fushi Tarazu Transcription Factors; D005786:Gene Expression Regulation; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D010750:Phosphoproteins / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D000098682:Steroidogenic Acute Regulatory Protein
D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; C515057:NR5A1 protein, human; D010750:Phosphoproteins; D016329:Sp1 Transcription Factor; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D000098682:Steroidogenic Acute Regulatory Protein; C515058:steroidogenic factor 1, mouse; D008156:Luciferases; D005982:Glutathione Transferase