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

• Published in: The Journal of biological chemistry 1998-01, Vol.273 (1), p.495-505
• Main Authors: Di Matteo, Gigliola, Salerno, Massimiliano, Guarguaglini, Giulia, Di Fiore, Barbara, Palitti, Franco, Lavia, Patrizia
• Format: Article
• Language: English
• Subjects: 3T3 Cells; Animals; Base Sequence; Binding Sites; Cell Extracts; DNA Footprinting; DNA, Single-Stranded - metabolism; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Fibroblasts - metabolism; GTP-Binding Proteins - genetics; Liver - metabolism; Mice; Molecular Sequence Data; Mutation; Nuclear Proteins - genetics; Promoter Regions, Genetic; Proteins - genetics; ran GTP-Binding Protein; Receptors, Retinoic Acid - genetics; Receptors, Retinoic Acid - metabolism; Retinoid X Receptors; RNA-Binding Proteins; Transcription Factors - genetics; Transcription Factors - metabolism; Transcriptional Activation
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.273.1.495

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.