Capturing nuclear sequence-specific DNA-binding proteins by using simian virus 40-derived minichromosomes.
We have used recombinant simian virus 40 (SV40) minichromosomes to retrieve sequence-specific DNA-binding proteins derived from the cell nucleus of COS-7 cells. We showed that the transcription factors AP-1 and Sp1 are stably bound to the SV40 DNA late in viral infection. Under similar conditions, minichromosomes carrying the rat insulin (rINS1) enhancer, which is under negative regulation in COS-7 cells, bound two proteins which mapped to distinct regions of the rINS1 enhancer. The SV40 P element competed for one of these proteins which bound to the region from -198 to -230. This factor may be related to AP-1. The other factor selectively bound a regulatory element in the region from -92 to -124 of the insulin enhancer. These proteins may play a role in regulating the rINS1 enhancer function.
Nir
U
U
Hormone Research Institute, University of California, San Francisco 94143-0534.
Fodor
E
E
Rutter
W J
WJ
D000818:Animals; D002460:Cell Line; D002472:Cell Transformation, Viral; D002875:Chromosomes / Q000502:physiology; D004279:DNA, Viral / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D010957:Plasmids; D011401:Promoter Regions, Genetic; D013539:Simian virus 40 / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D014157:Transcription Factors