Groner B, Ponta H, Rahmsdorf U, Herrlich P, Pfahl M, Hynes N E
J Steroid Biochem. 1984 Jan;20(1):95-8. doi: 10.1016/0022-4731(84)90194-8.
The molecular details of glucocorticoid hormone regulation of expression of the mouse mammary tumor virus (MMTV) proviral gene have been investigated. Cloned proviral DNA was introduced into cultured cells by a gene transfer procedure. DNA acquired by transfection was shown to be expressed in a hormone regulated fashion. The proviral DNA was fragmented and recombined in vitro with an indicator gene to delimit the hormone response sequence. Inducibility of the indicator gene (thymidine kinase gene from Herpes Simplex Virus, tk) was observed upon recombination with the long terminal repeat (LTR) sequence of MMTV. Further delimitation of the LTR DNA demonstrated that 202 nucleotides located 5' of the RNA initiation site are sufficient to confer glucocorticoid regulation. In vitro interaction of LTR DNA with glucocorticoid hormone receptor complex, showed a preferential affinity to the same sequence which mediated hormonal regulation in transfected cells. Evidence for a direct receptor gene interaction in the process of gene induction was gained by the measurement of the kinetics of induction and the use of a glucocorticoid antagonist (RU 486). The induction of the transfected gene is very rapid, independent of simultaneous protein synthesis and requires a functional glucocorticoid receptor hormone complex.
对糖皮质激素调节小鼠乳腺肿瘤病毒（MMTV）前病毒基因表达的分子细节进行了研究。通过基因转移程序将克隆的前病毒DNA导入培养细胞。转染获得的DNA显示以激素调节的方式表达。将前病毒DNA片段化并在体外与指示基因重组以界定激素反应序列。与MMTV的长末端重复序列（LTR）重组后观察到指示基因（单纯疱疹病毒胸苷激酶基因，tk）的诱导性。对LTR DNA的进一步界定表明，位于RNA起始位点5'端的202个核苷酸足以赋予糖皮质激素调节作用。LTR DNA与糖皮质激素受体复合物的体外相互作用显示对转染细胞中介导激素调节的相同序列具有优先亲和力。通过测量诱导动力学和使用糖皮质激素拮抗剂（RU 486）获得了基因诱导过程中直接受体基因相互作用的证据。转染基因的诱导非常迅速，与同时进行的蛋白质合成无关，并且需要功能性的糖皮质激素受体激素复合物。
