| Autor: |
Chamberlain SH; Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755-3844., Hemmer RM, Brinckerhoff CE |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of cellular biochemistry [J Cell Biochem] 1993 Jul; Vol. 52 (3), pp. 337-51. |
| DOI: |
10.1002/jcb.240520310 |
| Abstrakt: |
In rabbit fibroblasts the AP-1 sequence (5'-ATGAGTCAC-3') is necessary but not sufficient for induction of collagenase transcription by phorbol esters (PMA) (Auble and Brinckerhoff: Biochemistry 30(18):4629-4635, 1991). In this study we identified additional sequences involved in PMA-induced transcription. Using fibroblasts transiently transfected with chimeric constructs containing fragments of the rabbit collagenase 5'-flanking DNA linked to the chloramphenicol acetyl transferase (CAT) gene, we found that deletion of nucleotides -182 to -141 in a 380 bp promoter construct resulted in about a 7-fold loss of induction by PMA. Mobility shift assays revealed that nuclear proteins from fibroblasts specifically bound to 20-bp at -182 to -161. Binding was competed completely by self and only partially by the AP-1 sequence, implying that proteins binding to the AP-1 sequence could also bind to this region. In vitro transcribed and translated c-Fos and c-Jun bound to both the AP-1 site and to the sequences from -182 to -141. DNAase I footprinting of the collagenase promoter with purified c-Jun or c-Fos/c-Jun protected the AP-1 sequence at -77 to -69 in addition to a region from -189 to -178 which overlaps a putative AP-1-like site, 5'-ATTAATCAT-3'. Finally, deletion of the -182 to -161 region in a 380-bp CAT construct resulted in a substantial reduction of PMA responsiveness. Thus, we have identified a novel phorbol-responsive region that binds c-Fos and c-Jun, and we suggest that these or similar proteins may regulate transcription of the collagenase gene by binding to sequences within and adjacent to the -182 to -161 region. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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