Translational Control of Radiation-Induced Apoptosis

描述（由申请人提供）：本研究将主要在俄罗斯普希诺的俄罗斯科学院蛋白质研究所与A. S. Spirin作为NIH批准号RC1 AI078513的扩展。我们最近发现了一种新的细胞内信号转导途径参与调节哺乳动物的辐射敏感性。该途径由延伸因子2激酶（eEF 2K）介导，这是全球蛋白质合成的关键调节因子。我们发现，小鼠中该途径的失活可以赋予对γ辐射的致死效应的抗性，并且还防止辐射诱导的毛发变灰和辐射诱导的肠细胞凋亡。母提案的目标是表征这种新的信号转导途径，并开发可用于保护组织（特别是胃肠道组织）免受辐射损伤的新方法。在我们的初步实验中，我们发现，在缺乏eEF2K的细胞中，抗凋亡蛋白FLIP和XIAP的下调被阻断，这表明eEF2K对eEF2的磷酸化通过抑制短寿命抗凋亡蛋白的合成来刺激辐射诱导的凋亡。我们进一步提供了证据表明eEF 2K在翻译水平上调节抗凋亡蛋白的表达。该提案的目标是确定eEF2磷酸化控制短寿命抗凋亡蛋白翻译的分子机制。这将通过使用各种无细胞翻译系统和方法在蛋白质研究所开发的A。S.斯皮林和他的同事们。 公共卫生相关性：辐射诱导的细胞凋亡的翻译控制。 我们最近发现，在小鼠中的蛋白质合成调节因子eEF 2激酶的失活可以赋予对γ辐射的致死效应的抗性，并且还可以防止辐射诱导的毛发变白和辐射诱导的肠细胞凋亡。在我们的初步实验中，我们发现eEF 2激酶的敲除通过防止短寿命抗凋亡蛋白的下调来保护细胞免受辐射诱导的凋亡。该提案的目标是确定eEF2激酶控制短寿命抗凋亡蛋白翻译的分子机制，从而调节辐射抗性。这项研究将与俄罗斯科学院蛋白质研究所合作完成，俄罗斯普希诺，与A。S. Spirin作为NIH批准号RC1 AI078513的扩展。

DESCRIPTION (provided by applicant): This research will be done primarily at the Institute of Protein Research, Russian Academy of Sciences, Puschino, Russia, in collaboration with professor A. S. Spirin as an extension of NIH grant No. RC1 AI078513. We have recently discovered a novel intracellular signal transduction pathway involved in the regulation of radiation sensitivity in mammals. This pathway is mediated by the elongation factor 2 kinase (eEF2K), a key regulator of global protein synthesis. We found that inactivation of this pathway in mice can confer resistance to the lethal effects of gamma radiation and also protects against radiation-induced hair graying and radiation- induced apoptosis in intestinal cells. The goal of the parent proposal is to characterize this novel signal transduction pathway and to develop new approaches that can be used to protect tissues particularly of gastrointestinal tract from radiation damage. In our preliminary experiments we found that downregulation of anti-apoptotic proteins FLIP and XIAP is blocked in cells lacking eEF2K, suggesting that phosphorylation of eEF2 by eEF2K stimulates radiation-induced apoptosis by inhibiting synthesis of short-lived anti-apoptotic proteins. We further provided evidence that eEF2K regulates expression of anti-apoptotic proteins at the level of translation. The goal of this proposal is to determine the molecular mechanism by which eEF2 phosphorylation controls translation of short-lived anti-apoptotic proteins. This will be achieved by using various cell-free translation systems and methods developed at the Institute of Protein Research by A. S. Spirin and his colleagues. PUBLIC HEALTH RELEVANCE: Translational control of radiation-induced apoptosis. We have recently found that inactivation of a protein synthesis regulator eEF2 kinase in mice can confer resistance to the lethal effects of gamma radiation and also protects against radiation-induced hair graying and radiation-induced apoptosis in intestinal cells. In our preliminary experiments we found that knockout of eEF2 kinase protects cells from radiation-induced apoptosis by preventing down-regulation of short-lived anti- apoptotic proteins. The goal of this proposal is to determine the molecular mechanism by which eEF2 kinase controls translation of short-lived anti-apoptotic proteins and therefore modulates radiation resistance. This research will be done in collaboration with the Institute of Protein Research, Russian Academy of Sciences, Puschino, Russia, in collaboration with professor A. S. Spirin as an extension of NIH grant No. RC1 AI078513.