The First Intron of the Human Osteopontin Gene Contains a C/EBP-Beta-Responsive Enhancer
- 1 January 2003
- journal article
- research article
- Published by Xia & He Publishing in Gene Expression
- Vol. 11 (2) , 95-104
- https://doi.org/10.3727/000000003108748991
Abstract
The osteopontin (OPN) protein is found expressed at high level in several processes including fibrotic evolution of organ injuries, tumorigenesis, and immune response. The molecular mechanisms that underly overexpression, especially at the transcriptional level, have been only partially clarified. Therefore, this study was undertaken in search for additional DNA elements in the regulatory regions of the OPN gene and cognate transcription factors. Our results on the region upstream of the transcription start site confirmed that essential elements are located within the first 100 bp. Analysis of the sequence that includes the first untranslated exon and first intron revealed that it could enhance the promoter activity. Experiments of transfection of constructs containing different fragments of this sequence showed that most of the enhancer activity was confined in the terminal 30-bp tract of the first intron, although it was not functioning in a myofibroblast cell line. DNA/protein binding assays and cotransfection experiments showed that the C/EBP-beta transcription factor was able to bind a recognition sequence in this 30-bp segment. We found a bi-allelic sequence polymorphism at +245 in the first intron, which did not show a significant functional effect, but is a useful tool for future association studies.Keywords
This publication has 20 references indexed in Scilit:
- CCAAT/Enhancer-binding Proteins (C/EBP) β and δ Activate Osteocalcin Gene Transcription and Synergize with Runx2 at the C/EBP Element to Regulate Bone-specific ExpressionPublished by Elsevier ,2002
- Thirteen single-nucleotide polymorphisms in the human osteopontin gene identified by sequencing of the entire gene in Japanese individualsJournal of Human Genetics, 2001
- Osteopontin as a means to cope with environmental insults: regulation of inflammation, tissue remodeling, and cell survivalJournal of Clinical Investigation, 2001
- Transcriptional regulation of the human osteopontin promoter: functional analysis and DNA-protein interactionsOncogene, 2000
- Altered wound healing in mice lacking a functional osteopontin gene (spp1).Journal of Clinical Investigation, 1998
- Structure of the Osteopontin Gene and Its PromoteraAnnals of the New York Academy of Sciences, 1995
- A Single Cis-acting Element in a Short Promoter Segment of the Gene Encoding the Interphotoreceptor Retinoid-binding Protein Confers Tissue-specific ExpressionPublished by Elsevier ,1995
- IL-6DBP, a nuclear protein involved in interleukin-6 signal transduction, defines a new family of leucine zipper proteins related to CEBPCell, 1990
- A general method ofin vitropreparation and specific mutagenesis of DNA fragments: study of protein and DNA interactionsNucleic Acids Research, 1988
- Accurate transcription initiation by RNA polymerase II in a soluble extract from isolated mammalian nucleiNucleic Acids Research, 1983