Intracellular Domain Elements in the Regulation of EGF Receptor Kinase Activity

表皮生长因子受体（EGFR）的异常信号传导是导致几种人类免疫缺陷的原因。 癌症，并且是临床使用和/或试验中许多治疗剂的靶标。 最近对EGFR的分离的细胞外和激酶结构域的研究提供了 对这一重要受体的调控有重要的见解。其中一个关键的教训， 然而，EGFR是变构调节的， 区域-包括细胞质质膜（JM）和羧基末端（CT） 这些区域还没有被很好地理解，并且通常从实验中被忽略， 研究结构。我们最近发现EGFR的JM区含有一个 重要的激活结构域，并窝藏新的，但罕见的激活突变中发现， 肺癌患者。几项研究进一步表明，CT区域是必要的， 激酶激活的方式脱离其作为受体的位点的作用， 自磷酸化该区域也被认为含有自抑制结构域。在 根据这项提议，我们将扩展EGFR JM激活结构域（JMAD）的研究， 其他ErbB受体，它是保守的-从而获得新的见解调节 ErbB-2和ErbB- 4。我们还提出了实验来阐明如何大CT区域 调节EGFR激酶活性，以及它是否独立地或与EGFR激酶活性相关。 JM地区。在卡彭特和莱蒙实验室的合作下， 我们将结合联合收割机对整个受体胞内结构域（ICD）的生化分析， 通过研究完整受体来研究JM的生理相关性， 控制EGFR（和其他ErbB受体）的CT区域，及其对 配体依赖性信号传导和有丝分裂。体外生物物理和结构分析 也将追求，以获得详细的机械理解，将 建议药理学干预的方法。最后，司法部长和CT的作用 区域将在EGF受体构建体中进行评估，所述EGF受体构建体包括已知的激酶结构域， 激活突变，使肿瘤对临床上使用的激酶抑制剂敏感， 确定这些重要的调节元件如何相互合作， EGF受体的功能我们修订后的具体目标，我们有信心 可以在两年内完成的，有：1A。为了确定JM激活是否 结构域在ErbB-2和-4中是功能保守的。2.为了确定 大调节CT区的EGFR自身抑制。3.调查JM和 NSCLC突变在EGFR活化中相互作用。

Aberrant signaling by the EGF receptor (EGFR) is responsible for several human cancers, and is the target of a number of therapeutic agents in clinical use and/or trials. Recent studies of the isolated extracellular and kinase domains of EGFR have provided significant insights into the regulation of this important receptor. One of the key lessons, however, has been that the EGFR is allosterically regulated, with contributions from all regions - including the cytoplasmic juxtamembrane (JM) and carboxyterminal (CT) regions that are not well understood and have typically been omitted from experimentally studied constructs. We recently showed that the JM region of EGFR contains an important activation domain, and harbors novel but rare activating mutations found in lung cancer patients. Several studies further indicate that the CT region is required for kinase activation in a manner divorced from its role as the site for receptor autophosphorylation. This region is also thought to contain an auto-inhibitory domain. In this proposal, we will extend our studies of the EGFR JM activation domain (JMAD) to other ErbB receptors in which it is conserved - thus gaining new insight into regulation of ErbB-2 and ErbB- 4. We also propose experiments to elucidate how the large CT region regulates EGFR kinase activity, and whether it does so independently or in concert with the JM region. In a collaborative effort between the Carpenter and Lemmon laboratories, we will combine biochemical analyses of entire receptor intracellular domains (ICDs) with studies of the intact receptors to investigate the physiologic relevance of the JM and CT regions in the control of EGFR (and other ErbB receptors), and their importance for ligand-dependent signaling and mitogenesis. In vitro biophysical and structural analyses will also be pursued in order to gain a detailed mechanistic understanding that will suggest approaches for pharmacological intervention. Finally, the roles of the JM and CT regions will be evaluated in EGF receptor constructs that include known kinase domain- activating mutations that sensitize tumors to clinically employed kinase inhibitors - thus determining how these important regulatory elements cooperate with one another in controlling the intact EGF receptor. Our revised Specific Aims, which we are confident can be completed within two years, are: 1A. To determine whether the JM activation domain is functionally conserved in ErbB-2 and -4. 2. To determine the mechanism of EGFR autoinhibition by the large regulatory CT region. 3. To investigate how JM and NSCLC mutations interact in EGFR activation.