Transactivation of glucocorticoid-inducible rat aryl sulfotransferase (SULT1A1) gene transcription
Transactivation of glucocorticoid-inducible rat aryl sulfotransferase (SULT1A1) gene transcription
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DOI：
10.1124/dmd.31.11.1378
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发表时间：
2003-11-01
影响因子：
3.9
通讯作者：
Runge-Morris, M
中科院分区：
文献类型：
--
作者：
Fang, HL;Shenoy, S;Runge-Morris, M
本研究的目的是确定糖皮质激素受体(GR)和雄激素受体(AR)转录因子在大鼠芳基磺基转移酶(SULT1A1)基因转录反式激活中的作用，并确定SULT1A1基因中的功能性激素反应元件(S)。在SULT1A1基因5‘侧翼发现了一个带有3个干预碱基的顺式作用反向重复序列(IR3)，它介导了GR和AR对SULT1A1基因转录的反式激活。将SULT1A1-荧光素酶报告质粒与野生型或突变型GR或AR表达载体共转染CV-1细胞。在表达野生型GR的共转染体中，用曲安奈德处理后，含有IR3的SULT1A1报告质粒中的荧光素酶活性增加了4到6倍。含有IR3的SULT1A1报告结构也可以通过合成雄激素R1881在与野生型而不是突变型AR共转染的细胞中被激活。在原代培养的大鼠肝细胞中，雄激素诱导的含IR3的SULT1A1报告载体的表达需要与AR表达载体共转染。通过突变GR和AR反应性元件的3‘半位点上的保守GT序列来靶向破坏SULT1A1 IR3。这些结果表明，大鼠SULT1A1基因5‘侧翼区的IR3元件足以通过GR和AR反式激活SULT1A1基因转录，并且在原代培养的大鼠肝细胞中，相对于GR，功能性AR活性降低。
The purpose of the current study was to establish the role of the glucocorticoid receptor (GR) and androgen receptor (AR) transcription factors in the transactivation of rat aryl sulfotransferase (SULT1A1) gene transcription and to identify the functional hormone-responsive element(s) in the SULT1A1 gene. A cis-acting inverted repeat with three intervening bases (IR3) was identified in the 5'-flanking of the SULT1A1 gene that mediates the transactivation of SULT1A1 gene transcription by both the GR and AR. CV-1 cells were cotransfected with SULT1A1-luciferase reporter plasmids and either wild-type or mutant GR or AR expression constructs. In cotransfectants expressing the wild-type GR, treatment with triamcinolone acetonide produced an similar to4- to 6-fold induction of luciferase activity in IR3-containing SULT1A1 reporter plasmids. IR3-containing SULT1A1 reporter constructs were also activated by treatment with the synthetic androgen R1881 in cells cotransfected with wild-type but not mutant AR. In primary cultured rat hepatocytes, androgen-inducible expression of IR3-containing SULT1A1 reporter plasmids required cotransfection with AR expression plasmid. Targeted disruption of the SULT1A1 IR3 by mutation of a conserved GT sequence in the 3' half-site of the element ablated GR and AR responsiveness. These results indicate that a proximal IR3 element in the 5'-flanking region of the rat SULT1A1 gene is sufficient for the transactivation of SULT1A1 gene transcription by the GR and AR, and that relative to the GR, functional AR activity is reduced in primary cultured rat hepatocytes.