AUXILIARY PROTEINS IN THE RESPONSE TO THYROID HORMONE

甲状腺激素对正常发育和维持 正常的新陈代谢 它们影响代谢率，中间代谢， 以及肺、骨骼系统和中枢神经系统的生长和发育 神经系统 甲状腺激素的作用主要是由 甲状腺核受体（TR），与特定片段结合 甲状腺激素反应元件（TRE）和调节基因 通过未知机制转录。 一种叫做TR的核蛋白 辅助蛋白（TRAP），最近已被证明可以提高能力， 与DNA结合。 TRAP是一种序列特异性DNA结合蛋白 其似乎与TR形成异二聚体。 长期目标是 项目的目的是了解TRAP在TR功能中的作用。 的 第一个具体目标是表征TRAP所针对的DNA序列。 绑定。 用足迹法研究TRAP与DNA的相互作用 分析，以及TRAP DNA结合位点和 将在几个TREs中检查TRDNA结合位点。第二 具体目的是分离和表征TRAP cDNA克隆。克隆 将通过用TRAP筛选1gt 11表达文库来分离 DNA结合序列;或通过纯化TRAP，微测序 蛋白质，并基于该蛋白质用寡核苷酸筛选文库。 蛋白质序列将检查cDNA序列， 与转录因子家族相似。第三个具体目标 研究TRAP在T3应答中的作用。转染研究 将检查不同的TREs调节表达的能力， 报告基因，以及TRA内点突变的影响 DNA结合位点。此外，TRAP对T3反应的影响将是 通过转染TRAP cDNA或表达TRAP 反义RNA第四个具体目标是研究 不同组织中TRAP mRNA的表达及TRAP家族的可能性 mRNA。第五个具体目标是检查生理调节 TRAP mRNA的表达。所有这些研究的数据将有助于 定义TRAP-TR-DNA复合物的结构，以及TRAP在 T3反应。

Thyroid hormones are essential for normal development and maintenance of normal metabolism. They affect metabolic rate, intermediary metabolism, and growth and development of the lungs, skeletal system, and central nervous system. The effects of thyroid hormone are largely mediated by nuclear thyroid hormone-receptors (TR), which bind to specific segments of DNA (thyroid hormone response elements; TRE) and regulate gene transcription by an unknown mechanism. A nuclear protein, called TR auxiliary protein (TRAP), has recently been shown to enhance the ability of TR to bind to DNA. TRAP is a sequence-specific DNA-binding protein which appears to form heterodimers with TR. The long-term goal of this project is to understand the role of TRAP in the function of TR. The first specific aim is to characterize the DNA sequence to which TRAP binds. The interactions of TRAP with DNA will be studied by footprint analysis, and the relative positions of the TRAP DNA-binding site and the TR DNA-binding site will be examined in several TREs. The second specific aim is to isolate and characterize a TRAP cDNA clone. The clone will be isolated by screening 1gt11 expression libraries with the TRAP DNA-binding sequence; or by purification of TRAP, microsequencing the protein, and screening libraries with oligonucleotides based on the protein sequence. The sequence of the cDNA will be examined for similarity to families of transcription factors. The third specific aim is to study the role of TRAP in the response to T3. Transfection studies will examine the ability of different TREs to regulate expression of a reporter gene, and the effect of point mutations within the TRA DNA-binding site. Also, the effect of TRAP on the response to T3 will be investigated by transfection of the TRAP cDNA, or expression of TRAP antisense RNA. The fourth specific aim is to study the expression of TRAP mRNA in different tissues and the possibility of a family of TRAP mRNAs. The fifth specific aim is to examine the physiological regulation of expression of TRAP mRNA. The data from all these studies will help define the structure of the TRAP-TR-DNA complex, and the role of TRAP in the T3 response.