Genetic and Molecular Approaches to Signaling by Intracellular Receptors

9604938山本技术部分继续研究转录调节器整合信号信息的分子机制有五个具体目标。1.扩展对包括Hsp90和其他成分的专门分子伴侣复合体的分析，以探讨它使已知的最大类调节器--细胞内受体(IR)对其激素配体敏感的机制，并测试伴侣复合体本身是向脱辅酶受体传递信息的信号组件的可能性；2.寻求发现，反应元件，IRS与之结合的基因组位置，传递影响元件施加的转录调节模式的信号信息，例如，激活或抑制；分析响应元件的内在信号以及受体内的感知和解释机制；3.对糖皮质激素受体(GR)和甲状腺受体(TR)的激素结合域进行广泛的分析，寻找其共同和独特的机制；4.分离和鉴定首次从酵母中分离的选择性输出某些类固醇的ABC转运蛋白的哺乳动物同源物；寻找影响类固醇细胞内有效性和效力的其他成分，并确定这些膜成分是否有助于激素活性的细胞特异性；5.研究GR磷酸化的功能后果，并测试最近检测到的GR和TR与被称为INKS的细胞周期蛋白依赖性激酶抑制剂的相互作用导致受体和/或CDK活性改变从而构成信号整合电路的可能性。在多细胞真核生物中，非技术性片段基因受到复杂的调控，通常在不同的细胞类型、发育阶段或生理条件下受到不同的调控。理解这种复杂性的机制是现代生物学的首要问题。很明显，许多转录调节因子，即直接或间接与RNA聚合机制相互作用的因子，位于信号转导通路的末端，这些信号转导通路感知各种生物信号并沿着网络传递信息。

9604938 Yamamoto Technical Section There are five specific aims for this continuing investigation into the molecular mechanisms at several levels whereby signaling information is integrated by transcription regulators. 1. Extend the analysis of a specialized molecular chaperone complex, which includes Hsp90 and other components, to approach the mechanism by which it 'poises' the largest known class of regulators, the intracellular receptors (IRs)to be sensitive to their hormonal ligands, and to test the possibility that the chaperone complex is itself a signaling component that conveys information to aporeceptors; 2. Pursue findings that response elements, genomic sites to which IRs bind, confer signaling information that influences the mode of transcriptional regulation, e.g., activation or repression, that is imposed from the element; analyze both the signals intrinsic to the response elements and the sensing and interpretation mechanism within the receptors; 3. Carry out extensive analysis of the hormone binding domains of the glucocorticoid receptor (GR) and the thyroid receptor (TR), seeking common and unique features of their mechanisms; 4. Isolate and characterize a mammalian homolog of an ABC transporter first isolated in yeast that selectively exports certain steroids; seek other components that affect intracellular efficacy and potency of steroids, and ascertain whether such membrane components contribute to the cell specificity of hormone activity; 5. Investigate the functional consequences of GR phosphorylation, and test the possibility that recently detected interactions of GR and TR with cyclin-dependent kinase inhibitors termed INKs result in alterations of receptor and/or CDK activities and thereby comprise a signal integration circuit. Non-technical Section Genes in multicellular eukaryotes are subject to complex regulation, typically being regulated differentially in different cell types, developmental stages or physiological conditions. Understanding the mecha nisms of this complexity is an overarching problem in modern biology. It is apparent that many transcription regulators, factors that interact directly or indirectly with the RNA polymerization machinery, are at the distal end of signal transduction pathways that sense various biological signals and pass that information along a network.