REGULATION OF GLUCOCORTICOID RECEPTOR FUNCTION BY CAMP

总体目标是更好地理解 糖皮质激素和激素的作用机制 通过cAMP调节淋巴的活性和生长。两种类固醇 和环核苷酸被证明有能力抑制 作为有机体对压力反应的一部分的免疫系统。 已知这些药物的主要转导分子是一种基因- 调节受体和一种蛋白激酶，但立即 人们对它们所影响的功能只有部分了解。证据 提出了交叉调节，表明cAMP具有 促进糖皮质激素结合能力的提高 小鼠淋巴瘤细胞系WEHI-7。两种可能的机制是 提议：1)将隐蔽的受体池转换为 活性形式；2)受体蛋白合成增加。这个 我们将研究受体修饰与合成的关系。 使用2D-凝胶电泳法，硫氧还蛋白测定，密度梯度 受体蛋白和受体合成的分析和分子探针 信使核糖核酸。 在T细胞分化的某些阶段，糖皮质激素和 环核苷酸可以引起细胞溶解反应。此行为 为使用类固醇治疗糖尿病提供了依据。 某些形式的白血病。细胞溶解反应也有 提出了一种用于选择包含以下内容的抗性变体的工具 糖皮质激素受体改变与环磷酸腺苷依赖蛋白 激活剂。这份提案涉及到这一发现和 “第二代”类固醇/环状化合物的表征 核苷酸抗性变异体。研究发现，交流声母 小鼠淋巴瘤WEHI-7 ACTs对cAMP耐药的筛选 作为S选择类固醇耐药的许可步骤 频率很高。结果表明，具有 代表了新形式的类固醇耐药性，可能 涉及激活糖皮质激素受体进入 类固醇结合状态。这些变异细胞的特征 线条的提出是为了识别改变后的功能 从而导致功能性受体的丧失。

The overall goal is to achieve a greater understanding of the mechanisms by which glucocorticoid hormones and hormones which act through cAMP regulate lymphoid viability and growth. Both steroids and cyclic nucleotide have the demonstrated capacity to suppress the immune system as a part of an organism's response to stress. The primary transducers for these agents are known to be a gene- regulating receptor and a protein kinase, but the immediate functions that they affect are only partially understood. Evidence of crossregulation is presented, showing that cAMP has the ability to promote an increase of glucocorticoid binding capacity in a murine lymphoma line, WEHI-7. Two possible mechanisms are proposed: 1) Conversion of a cryptic pool of receptors into an active form; 2) Increased synthesis of receptor protein. The involvement of receptor modification vs. synthesis will be studied using 2D-gel electrophoresis, thioredoxin assays, density gradient analysis and molecular probes for synthesis of receptor protein and messenger RNA. At certain stages of T-cell differentiation, glucocorticoids and cyclic nucleotide can elicit a cytolytic response. This behavior has provided a basis for the use of steroids in treatment of certain forms of leukemia. The cytolytic response has also presented a tool for selection of resistant variants containing altered glucocorticoid receptors and cyclic AMP-dependent protein kinase. This proposal deals with the discovery and characterization of a "second generation" of steroid/cyclic nucleotide resistant variants. It was found that ac initial selection for resistance to cAMP in the murine lymphoma WEHI-7 acts as a permissive step towards selection of steroid resistance at s high frequency. The results indicate that the variants which have been obtained represent new forms of steroid resistance, possibly involving functions that activate the glucocorticoid receptor into a steroid binding state. Characterization of these variant cell lines is proposed in an attempt to identify the altered functions which lead to the loss of functional receptor.