Intracellular Domain Elements in the Regulation of EGF Receptor Kinase Activity

表皮生长因子受体(EGFR)的异常信号与几种人类 治疗癌症，是一些临床使用和/或试验中的治疗药物的靶标。 最近对分离的EGFR胞外区和激动区的研究提供了 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是， 然而，一直以来，EGFR受到变构监管，所有人都做出了贡献 区域--包括细胞质近膜(JM)和羧基末端(CT) 不被很好地理解并且通常在实验中被省略的区域 研究了结构。我们最近发现，EGFR的JM区包含一个 重要的激活结构域，并含有新的但在 肺癌患者。几项研究进一步表明，CT区域是 以一种脱离其作为受体位置的角色的方式激活 自动磷酸化。这一区域也被认为含有一个自我抑制结构域。在……里面 在这项提议中，我们将把我们对EGFR JM激活结构域(JMAD)的研究扩展到 它保守的其他ErbB受体-从而获得了对 ErbB-2和ErbB-4。我们还提出了实验来阐明大CT区域如何 调节EGFR激酶的活性，以及它是独立地还是与 JM地区。在卡彭特和莱蒙实验室的合作中， 我们将结合对整个受体细胞内域(ICD)的生化分析 通过对完整受体的研究，探讨JM和JM的生理学相关性 控制EGFR(和其他ErbB受体)的CT区域及其对 配体依赖的信号转导与有丝分裂。体外生物物理和结构分析 也将继续进行，以便获得详细的机械性理解， 建议药物干预的方法。最后，JM和CT的作用 这些区域将在EGF受体结构中进行评估，其中包括已知的激活域- 激活突变，使肿瘤对临床使用的激酶抑制剂敏感-因此 确定这些重要的监管要素如何在 控制完整的EGF受体。我们修订的具体目标，我们对此充满信心 可以在两年内完成，分别是：1A。以确定JM激活是否 在ErbB-2和-4中，结构域在功能上是保守的。2.确定其作用机制。 EGFR自身受大调控CT区域的抑制。3.调查JM和 NSCLC突变与EGFR激活相互作用。

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.