REGULATORY SEQUENCES OF THE HUMAN HPRT GENE

次黄嘌呤磷酸核糖基转移酶(HPRT)是 在除部分组织外的所有组织中都有低水平的组成性表达 在中枢神经系统中，它在五到五分钟内表达 高出八倍的水平。该酶在体内完全缺乏 人类导致Lesch-Nyhan综合征，一种X连锁的神经病 精神障碍的特征是智力低下，脉络膜机能不全， 自残行为和高尿酸血症。此应用程序 建议识别和准确描述顺式作用的积极因素 以及HPRT基因的负调控序列。删除 分析和体外诱变将被用来研究 这些序列在HPRT表达中的功能作用。转接- 与这些序列相互作用的作用因素将被识别 以及它们与表征的序列的相互作用。这些 因子将被提纯，表达它们的cDNA克隆将被 与世隔绝，以便了解它们在调节 HPRT基因和其他功能相关基因。转基因 携带报告基因的小鼠，E.Coliβ-半乳糖苷酶 与多种顺式作用调控序列连锁的基因 HPRT基因，将构建并表达报告基因在 包括大脑在内的各种组织被检查以确定体内 体内调控序列的作用。这些研究将 促进我们对组织差异基因表达的理解， 管家基因的表达和潜在的定义因素 导致中枢神经系统HPRT表达增加 吉恩。后一种信息在以下情况下将是有价值的 对Lesch-Nyhan患者中枢神经系统功能障碍的认识 在这种疾病的基因治疗方面也是如此。

The enzyme hypoxanthine phosphoribosyltransferase (HPRT) is constitutively expressed at low levels in all tissues except in parts of the central nervous system where it is expressed at five- to eight-fold higher levels. Total deficiency of this enzyme in humans causes Lesch-Nyhan syndrome, an X-linked neurological disorder characterized by mental retardation, chorioathetosis, self-mutilative behavior and hyperuricemia. This application proposes to identify and precisely delineate the cis-acting positive and negative regulatory sequences of the HPRT gene. Deletion analysis and in vitro mutagenesis will be used to study the functional role of these sequences in HPRT expression. Trans- acting factors interacting with these sequences will be identified and their interaction with the sequence characterized. These factors will be purified and cDNA clones expressing them will be isolated in order to understand their role in the regulation of the HPRT gene and other functionally-related genes. Transgenic mice that harbor a reporter gene, the E. Coli beta-galactosidase gene linked to the various cis-acting regulatory sequences of the HPRT gene, will be created and expression of the reporter gene in various tissues, including the brain, examined to determine the in vivo role of the regulatory sequences. These studies will facilitate our understanding of tissue-differential gene expression, housekeeping gene expression and potentially define the factors causing increased central nervous system expression of the HPRT gene. This latter information will be of value in the context of knowing the central nervous system dysfunction in Lesch-Nyhan syndrome and in gene therapy for this disease.