Hl. Brenza et al., PARATHYROID-HORMONE ACTIVATION OF THE 25-HYDROXYVITAMIN D-3-1-ALPHA-HYDROXYLASE GENE PROMOTER, Proceedings of the National Academy of Sciences of the United Statesof America, 95(4), 1998, pp. 1387-1391
The DNA flanking the 5' sequence of the mouse 1 alpha-hydroxylase gene
has been cloned and sequenced. A TATA box has been located at -30 bp
and aCCAAT box has been located at -79 bp. The gene's promoter activit
y has br!en demonstrated by using a luciferase reporter gene construct
transfected into a modified pig kidney cell line, AOK-B50. Parathyroi
d hormone stimulates this promoter-directed synthesis of luciferase by
17-fold, whereas forskolin stimulates it by 3-fold. The action of par
athyroid hormone is concentration-dependent. 1,25-Dihydroxyvitamin D-3
does not suppress basal promoter activity and marginally suppresses p
arathyroid hormone-driven luciferase reporter activity. The promoter h
as three potential cAMP-responsive element sites, and two perfect and
one imperfect AP-1 sites, while no DR-3 was detected. These results in
dicate that parathyroid hormone stimulates 25-hydroxyvitamin D-3-1 alp
ha-hydroxylase by acting on the promoter of the 1 alpha-hydroxylase ge
ne.