The invention provides a system for modulating the expression of a target gene in a subject wherein a defined response element for a DNA binding domain modulates expression of said target gene. The invention system comprises two chimeric proteins, each containing the dimerization domain of a member of the steroid/thyroid hormone nuclear receptor superfamily, one of which is non-endogenous to the subject. In addition, the first chimeric protein contains a DNA binding domain to which the target gene is responsive and the second chimeric protein contains a transcription modulating domain, such as a transcription activator or a transcription repressor. In one embodiment of the invention, two invention systems form a dimer having the properties of a native heterodimer or homodimer. In another embodiment, only the first chimeric protein contains a DNA binding domain and only the second chimeric protein contains a transcription activating domain. The functional entity formed by association of the first and second chimeric proteins can be designed to transactivate transcription by complexing with a DNA binding recognition site that does not have the 2-half site format common to response elements for members of the steroid/thyroid hormone nuclear receptor superfamily. Thus, certain of the invention systems cannot functionally interact with endogenous proteins in the way that wild type receptors do. The invention further provides nucleic acid sequences encoding the invention chimeric proteins, cells containing such nucleic acid sequences, and methods for using the invention chimeric proteins to modulate expression of one or more non-endogenous genes in a subject organism.
本发明提供了一种调节受试者体内靶
基因表达的系统,其中 DNA 结合结构域的确定反应元件可调节所述靶
基因的表达。本发明系统包括两个嵌合蛋白,每个嵌合蛋白都含有类
固醇/甲状腺激素核受体超家族成员的二聚化结构域,其中一个是受试者的非内源性蛋白。此外,第一个嵌合蛋白含有 DNA 结合结构域,靶
基因对其有反应;第二个嵌合蛋白含有转录调节结构域,如转录激活剂或转录
抑制剂。在本发明的一个实施方案中,两个发明系统形成的二聚体具有原生异源二聚体或同源二聚体的特性。在另一个实施方案中,只有第一个嵌合蛋白含有 DNA 结合结构域,只有第二个嵌合蛋白含有转录激活结构域。第一种和第二种嵌合蛋白结合形成的功能实体可通过与 DNA 结合识别位点复合来激活转录,该识别位点不具有类
固醇/甲状腺激素核受体超家族成员的反应元件所共有的 2-半位点格式。因此,本发明的某些系统不能像野生型受体那样与内源蛋白发生功能性相互作用。本发明进一步提供了编码本发明嵌合蛋白的核酸序列、含有此类核酸序列的细胞,以及使用本发明嵌合蛋白调节受试
生物体中一个或多个非内源
基因表达的方法。