ACTIVATED MUTANTS AS PROBES OF GM/CSF RECEPTOR FUNCTION

描述：(调查者摘要)本项目旨在调查 粒细胞-巨噬细胞集落刺激受体的功能 因子(GM-CSF)、白介素3(IL-3)、白介素5(IL-5)。这些 因子对髓系细胞具有很强的增殖分化作用 造血细胞，而且，自分泌的GM-CSF已经 与一些白血病有关，而IL-5与许多过敏症有关 反应。GM-CSF、IL-3和IL-5的细胞表面受体是 属于细胞因子受体家族，由两个不同的亚基组成， 阿尔法和贝塔。α亚基对每个因子都是唯一的，而β亚基 亚基(h-β-c)由三个因子共享。具体地说，它是 建议利用一组独特的构成活性的突变体 H-β-c，以考察其结构、组成和活性。 功能性受体复合体。这些研究将测试一个模型，该模型 预测实际上存在两种不同类型的功能性受体 很复杂。这将通过以下方式进行：(I)审查 在细胞系中表达的受体亚基；(Ii)分子研究 正常和突变形式的h-β-c临界区的结构。 这将同时使用定向突变和核磁共振 光谱学；(Iii)试图将不同的受体亚基相互关联 与h-β-c酪氨酸磷酸化的关系。此外，它是 提出了新的试剂(如单抗和多肽)可以 与h-β-c的关键区域相互作用，并且可以 触发它的信号活动。以及提供工具来探测 受体结构，这些试剂可以为 分离这些和其他细胞因子成员的新型激动剂 受体家族。

DESCRIPTION: (Investigator's abstract) This project aims to investigate the function of the receptors for granulocyte-macrophage colony stimulating factor (GM-CSF), Interleukin-3 (IL-3) and Interleukin-5 (IL-5). These factors exert strong proliferative and differentiative effects on myeloid hemopoietic cells, and moreover, autocrine GM-CSF production has been implicated in some leukemias, while IL-5 is involved in many allergic reactions. The cell-surface receptors for GM-CSF, IL-3 and IL-5 are members of the cytokine receptor family and are comprised of two different subunits, alpha and beta. The alpha subunit is unique to each factor while the beta subunit (h-beta-c) is shared by the three factors. Specifically, it is proposed to utilize a unique set of constitutively active mutants of the h-beta-c to examine the structure, composition and activity of the functional receptor complexes. These studies will test a model which predicts that there are actually two distinct types of functional receptor complex. This will be carried out by: (i) Examining association between receptor subunits expressed in cell lines; (ii) Studying the molecular structure of a critical region of h-beta-c in both normal and mutant forms. This will use both directed mutations and nuclear magnetic resonance spectroscopy; (iii) Attempting to correlate different receptor subunit associations with tyrosine phosphorylation of h-beta-c. In addition, it is proposed that novel reagents (e.g., monoclonal antibodies and peptides) can be generated which interact with critical regions of h-beta-c and which can trigger its signalling activity. As well as providing tools to probe receptor structure, these reagents may provide a proof-of-principle for the isolation of novel agonists for these and other members of the cytokine receptor family.