Darwish H M, Burmester J K, Moss V E, DeLuca H F
Department of Biochemistry, University of Wisconsin-Madison, College of Agricultural and Life Sciences.
Biochim Biophys Acta. 1993 Mar 17;1167(1):29-36. doi: 10.1016/0005-2760(93)90213-s.
The 1,25-dihydroxyvitamin D3 receptor becomes phosphorylated upon treatment with 1,25-dihydroxyvitamin D3. We have investigated the role of phosphorylation in the transcriptional activity induced by 1,25-dihydroxyvitamin D3 through its receptor. An active 1,25-dihydroxyvitamin D3-dependent transcription system was reconstituted in CV-1 cells by co-transfection of plasmids containing the rat 1,25-(OH)2D3 receptor DNA and a functional vitamin D response element (DRE) in a reporter gene construct. Treatment of these transiently transfected CV-1 cells with modulators of protein kinase A (8-Br-cAMP, PKIA and H-9) and phosphatases (Okadaic acid) resulted in mimicking or abolishing the transcriptional activity of 1,25-dihydroxyvitamin D3 in a receptor-dependent fashion. These modulators directly altered 1,25-dihydroxyvitamin D3 receptor phosphorylation. Therefore, the present results strongly suggest that phosphorylation plays a central role in the transcriptional activity of the 1,25-dihydroxyvitamin D3 receptor.
用1,25 - 二羟基维生素D3处理后，1,25 - 二羟基维生素D3受体发生磷酸化。我们研究了磷酸化在1,25 - 二羟基维生素D3通过其受体诱导的转录活性中的作用。通过在报告基因构建体中共转染含有大鼠1,25 - (OH)2D3受体DNA和功能性维生素D反应元件（DRE）的质粒，在CV - 1细胞中重建了一个活跃的1,25 - 二羟基维生素D3依赖性转录系统。用蛋白激酶A的调节剂（8 - Br - cAMP、PKIA和H - 9）和磷酸酶（冈田酸）处理这些瞬时转染的CV - 1细胞，导致以受体依赖性方式模拟或消除1,25 - 二羟基维生素D3的转录活性。这些调节剂直接改变了1,25 - 二羟基维生素D3受体的磷酸化。因此，目前的结果强烈表明磷酸化在1,25 - 二羟基维生素D3受体的转录活性中起核心作用。
