MOLECULAR STUDIES OF FC RECEPTORS FOR IMMUNOGLOBULIN E

肥大细胞和嗜碱性粒细胞上的IgE受体（Fcepsilone R-I）是 直接参与IgE介导的这些细胞的活化。 最近，编码大鼠Fcepsilone α-亚基的cDNA R-I（Fcepsilone R-Ialpha）已被克隆。 RNA异质性是 随后检测到，表明存在Fc的变体 epsilone R-I α，包括可能存在的细胞内 形式和分泌截短形式的Fc ε R-I α。 一个新 IgE结合蛋白，epsilone BP，被发现含有有趣的 结构特征，但其功能尚未明确。 在 在这项研究计划中，我们将继续研究Rc epsilone R-I和epsilone BP。 第一，啮齿动物Fecepsilone R-I的结构-功能关系 阿尔法将成立。 克隆的cDNA在哺乳动物中的表达 将进行基因转染的细胞。 两者的表达 受体的表面膜结合形式和可溶形式 将被追捕。 正常大鼠肥大细胞中的突变Fc ε R-I α 细胞 从cDNA克隆预测的各种蛋白质产物 结果，包括细胞内和分泌截短形式 将生成的Fcepsilone R-I样品用于结构-功能分析 分析，以鉴定 与IgE结合有关。 第二，将鉴定各种形式的FcepsiloneR-Ialpha。 RNA酶保护分析和聚合酶链反应方法学 将被用来鉴定各种RNA形式， 正常大鼠肥大细胞中的FcepsiloneR-I α。 各种蛋白质 从cDNA克隆结果预测的产物，包括 胞内和分泌性截短形式的FcepsiloneR-I α 将在RBL细胞中检测到。 编码小鼠的基因组DNA FCepsiloneR-Ialpha将被克隆并用于扩展上述 鼠标系统分析。 第三，新定义的IgE结合蛋白的功能 （epsiloneBP）将被描绘。 表达epsilone的细胞类型 并将鉴定ε-酮在细胞中的位置。 如果 已经确定ε-酮不是细胞表面受体， 作为一种可溶性蛋白，调节IgE合成或组胺 将探索肥大细胞和嗜碱性粒细胞的释放。 本研究的远期目标是：1）建立 IgE关键成分的结构、功能和调节 系统;和2）治疗方法的发展，用于治疗 人类过敏性疾病

The IgE receptor on mast cells and basophils (Fcepsilone R-I) is directly involved in the IgE-mediated activation of these cells. Recently, cDNA coding for the alpha-subunit of the rat Fcepsilone R-I (Fcepsilone R-Ialpha) has been cloned. RNA heterogeneity was subsequently detected, suggesting the presence of variants of Fc epsilone R-Ialpha, including the possible presence of intracellular forms and secretory truncated forms of Fc epsilone R-Ialpha. A new IgE-binding protein, epsilone BP, was found to contain interesting structural features, but its function is yet to be defined. In this research program, we will continue our studies of both Rc epsilone R-I and epsilone BP. First, structure-function relationship of rodent Fcepsilone R-I alpha will be established. Expression of cloned cDNA in mammalian cells by gene transfection will be conducted. Expression of both the surface membrane-bound form and soluble form of the receptor will be pursued. Mutant Fc epsilone R-I alpha in normal rat mast cells. Various protein products predicted from the cDNA cloning results, including the intracellular and secetory truncated forms of Fcepsilone R-I alphs will be generated for structure-function analysis to identify structural elements in FcepsiloneR-Ialphs that are involved in binding to IgE. Second, various forms of FcepsiloneR-Ialpha will be identified. RNase protection analysis and polymerase chain reaction methodology will be employed to identify various RNA forms related to FcepsiloneR-Ialpha in normal rat mast cells. Various protein products predicted from the cDNA cloning results, including the intracellular and secretory truncated forms of FcepsiloneR-Ialpha will be detected in RBL cells. Genomic DNA coding for mouse FCepsiloneR-Ialpha will be cloned and used to extend the above analysis to the mouse system. Third, function of the newly defiend IgE-binding protein (epsiloneBP) will be delineated. Cell types expressing epsilone and the location of epsilone in cells will be identified. If it is established that epsilone is not a cell suface receptor, its role as a soluble protein, regulating IgE synthesis or histamine release form mast cells and basophils will be explored. The long-term goals of this research are: 1) establishment of structure, function and regulation of key components of the IgE system; and 2) development of therapeutic methods for the treatment of human allergic disorders.