Identification of a suppressor element in the amelogenin promoter.
Amelogenin expression is regulated in a cell-type- specific manner. Investigators have previously identified an enhancer element by using the 5' flanking sequence of the amelogenin promoter. However, the cell-type-specific regulation of the amelogenin gene remains poorly understood. In some genes, the first intron regulates tissue-specific expression. We hypothesized that intron 1 is important for the cell-type-specific regulation of amelogenin expression. We identified a suppressor element between -74 and -464. We also found enhancer activity in intron 1. Additionally, we found that the suppressor element in the promoter region suppressed intron 1 enhancer activity. The suppressor and the enhancers acted in an ameloblast-like cell line, but not in HeLa cells. Mutation of the Oct-1 binding sites reversed the suppressor activity, suggesting that Oct-1 sites are essential for suppression. These results suggest that Oct-1 and intron 1 may contribute to cell-type-specific amelogenin expression.
Xu
L
L
Advanced Medical Materials Group, Biomaterials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Matsumoto
A
A
Sasaki
A
A
Harada
H
H
Taniguchi
A
A
D000565:Ameloblasts / Q000378:metabolism*; D053523:Amelogenin / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D007438:Introns / Q000235:genetics; D050811:Octamer Transcription Factor-1 / Q000235:genetics / Q000378:metabolism; D051381:Rats; D020218:Response Elements / Q000235:genetics*; D013489:Suppression, Genetic / Q000235:genetics*
D053523:Amelogenin; D050811:Octamer Transcription Factor-1