Stephanou A, Handwerger S
Department of Endocrinology, Children's Hospital Medical Center, University of Cincinnati College of Medicine, OH 45229, USA.
Mol Cell Endocrinol. 1995 Jul;112(1):123-9. doi: 10.1016/0303-7207(95)03598-2.
Three regions of the human placental lactogen (hPL) promoter that contain several half-site motifs that closely resemble the responsive elements for thyroid hormone (TR), all trans retinoic acid (RAR) and 1,25 dihydroxyvitamin D3 (VDR) have been identified and characterized. Transfection studies in BeWo choriocarcinoma cells indicate that site A (nt -979 to -954) is responsive to RAR alpha but not TR beta. Site B (nt -1140 to -1170) is responsive to both RAR alpha and TR beta, and site C (nt -550 to -580) is not responsive to either RAR alpha or TR. These findings, together with the observation that placental cells express retinoid receptors and TRs, strongly suggest a role for these receptors in the regulation of the hPL gene. Site B on the hPL promoter is able to integrate the responses to RA and T3 through a single element.
已鉴定并表征了人胎盘催乳素（hPL）启动子的三个区域，这些区域包含几个半位点基序，它们与甲状腺激素（TR）、全反式维甲酸（RAR）和1,25-二羟基维生素D3（VDR）的反应元件非常相似。在BeWo绒毛膜癌细胞中的转染研究表明，位点A（核苷酸-979至-954）对RARα有反应，但对TRβ无反应。位点B（核苷酸-1140至-1170）对RARα和TRβ均有反应，而位点C（核苷酸-550至-580）对RARα或TR均无反应。这些发现，连同胎盘细胞表达类视黄醇受体和TRs的观察结果，强烈表明这些受体在hPL基因的调控中起作用。hPL启动子上的位点B能够通过单个元件整合对RA和T3的反应。
