| First Author | Gill RK | Year | 1995 |
| Journal | Mol Endocrinol | Volume | 9 |
| Issue | 3 | Pages | 319-26 |
| PubMed ID | 7776978 | Mgi Jnum | J:23800 |
| Mgi Id | MGI:71489 | Doi | 10.1210/mend.9.3.7776978 |
| Citation | Gill RK, et al. (1995) Regulation by estrogen through the 5'-flanking region of the mouse calbindin-D28k gene. Mol Endocrinol 9(3):319-26 |
| abstractText | Mouse calbindin-D28k expression is regulated in vivo by estradiol in ovaries, uterus, and oviduct. To determine whether estrogen can have an effect on the transcription of the calbindin-D28k gene, the human breast cancer cells T47D were transiently transfected with a plasmid containing a 1.1 kilobase (kb) PstI/SacII fragment (-1075/+34) of the mouse calbindin gene ligated to the chloramphenicol acetyltransferase (CAT) gene and cotransfected with human estrogen receptor expression vector. T47D cells, transfected and treated with estradiol (10(-11) - 10(-7) M for 64-65 h), exhibited a dose-dependent increase in CAT activity (up to 6.2-fold). Transfection of MCF-7 breast cancer cells with the chimeric gene construct alone also resulted in an estradiol-dependent induction in CAT activity. Deletion mutant analysis demonstrated that there are two regions of the mouse calbindin-D28k promoter (between -1075/-702 and between -175/-78) that contribute to the induction by estradiol. These fragments, when linked to the thymidine kinase promoter to construct a heterologous promoter chimera, were able to convert the thymidine kinase promoter to estrogen responsiveness. In these regions there are multiple imperfect half-palindromic estrogen-responsive elements. Gel retardation assays demonstrated weak protein-DNA interactions that were competed with cold oligonucleotide containing the vitellogenin estrogen-response element. These findings indicate that the mouse calbindin-D28k promoter is capable of conferring estrogen responsiveness, which may be mediated by several imperfect half-palindromic estrogen-responsive elements, and suggest, in light of previous studies concerning 1,25-dihydroxyvitamin D regulation, multiple steroid regulation of the calbindin-D28k gene. |
