Interactions with single-stranded and double-stranded DNA-binding factors and alternative promoter conformation upon transcriptional activation of the Htf9-a/RanBP1 and Htf9-c genes.
The murine Htf9-a/RanBP1 and Htf9-c genes are divergently transcribed from a shared TATA-less promoter. Transcription of both genes is initiated on complementary DNA strands and is controlled by cell cycle-dependent mechanisms. The bidirectional promoter harbors a genomic footprint flanking the major transcription start site of both genes. Transient promoter assays showed that the footprinted element is important for transcription of both genes. Protein-binding experiments and antibody assays indicated that members of the retinoid X receptor family interact with the double-stranded site. In addition, distinct factors interact with single DNA strands of the element. Double-stranded binding factors were highly expressed in liver cells, in which neither gene is transcribed, while single-stranded binding proteins were abundant in cycling cells, in which transcription of both genes is efficient. In vivo S1 analysis of the promoter depicted an S1-sensitive organization in cells in which transcription of both genes is active; S1 sensitivity was not detected in conditions of transcriptional repression. Thus, the same element is a target for either retinoid X receptor factors, or for single-stranded binding proteins, and form distinct complexes in different cellular conditions depending on the DNA conformation in the binding site.
Di Matteo
G
G
CNR Centre of Evolutionary Genetics, c/o Department of Genetics and Molecular Biology, University "La Sapienza," Rome 00185, Italy.
Salerno
M
M
Guarguaglini
G
G
Di Fiore
B
B
Palitti
F
F
Lavia
P
P
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002457:Cell Extracts; D018983:DNA Footprinting; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics*; D008099:Liver / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011506:Proteins / Q000235:genetics*; D016601:RNA-Binding Proteins; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism; D047488:Retinoid X Receptors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D020931:ran GTP-Binding Protein
D002457:Cell Extracts; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011506:Proteins; D016601:RNA-Binding Proteins; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; C091775:ran-binding protein 1; C070847:Htf9c protein, mouse; D019204:GTP-Binding Proteins; D020931:ran GTP-Binding Protein