Please use this identifier to cite or link to this item:
https://scholarbank.nus.edu.sg/handle/10635/111826
DC Field | Value | |
---|---|---|
dc.title | Cloning and functional analysis of spliced isoforms of human nuclear factor I-X: Interference with transcriptional activation by NFI/CTF in a cell-type specific manner | |
dc.contributor.author | Apt, D. | |
dc.contributor.author | Liu, Y. | |
dc.contributor.author | Bernard, H.-U. | |
dc.date.accessioned | 2014-11-28T02:50:07Z | |
dc.date.available | 2014-11-28T02:50:07Z | |
dc.date.issued | 1994-09-25 | |
dc.identifier.citation | Apt, D.,Liu, Y.,Bernard, H.-U. (1994-09-25). Cloning and functional analysis of spliced isoforms of human nuclear factor I-X: Interference with transcriptional activation by NFI/CTF in a cell-type specific manner. Nucleic Acids Research 22 (19) : 3825-3833. ScholarBank@NUS Repository. | |
dc.identifier.issn | 03051048 | |
dc.identifier.uri | http://scholarbank.nus.edu.sg/handle/10635/111826 | |
dc.description.abstract | Previous studies of the epithelial specificity of the human papillomavirus type 16 (HPV-16) enhancer pointed to an important role of nuclear factor I (NFI). In epithelial cells, NFI proteins are derived from the NFI-C gene and referred to as NFI/CTF. In contrast, fibroblasts, where the enhancer is inactive, express high levels of NFI from the NFI-X gene. To compare NFI-C and NFI-X derived transcription factors, we cloned and functionally investigated two differentially spliced forms of NFI-X from human fibroblasts. NFI-X1 has 95% homology with a transcript previously identified in hamster liver cells. NFI-X2, a spliced variant, misses 41 amino acids of the proline-rich activation domain. NFI-X expression, examined by Northern blots, shows strong cell-type specific variation in comparison with NFI/CTF. While the transcriptional activation domain of NFI-X2, functionally tested as GAL4-fusion protein in epithelial and fibroblast cells, activates transcription from promoter as well as enhancer position similar to NFI/CTF-1, the activation domain of NFI-X1 fails to activate transcription from enhancer position. In Drosophila cells, void of endogenous NFI proteins, full length NFI/CTF-1 and NFI-X2 activate a reporter construct containing only NFI sites as well as the NFI dependent HPV-16 enhancer. In contrast, NFI-X1 fails to activate the HPV-16 enhancer. Furthermore, overexpression of NFI-X1 in epithelial cells downregulates the HPV-16 enhancer. Our findings suggest that the family of NFI transcription factors should not be viewed as constitutive activators, but rather, that NFI-C and NFI-X have divergent functions after binding in promoter or enhancer position. This property, combined with the differential expression of NFI-X, can achieve cell-type specificity of NFI dependent promoters and enhancers. | |
dc.source | Scopus | |
dc.type | Article | |
dc.contributor.department | INSTITUTE OF MOLECULAR & CELL BIOLOGY | |
dc.description.sourcetitle | Nucleic Acids Research | |
dc.description.volume | 22 | |
dc.description.issue | 19 | |
dc.description.page | 3825-3833 | |
dc.description.coden | NARHA | |
dc.identifier.isiut | NOT_IN_WOS | |
Appears in Collections: | Staff Publications |
Show simple item record
Files in This Item:
There are no files associated with this item.
Google ScholarTM
Check
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.