Translational Control of Radiation-Induced Apoptosis

描述(由申请人提供)：这项研究将主要在俄罗斯普斯奇诺的俄罗斯科学院蛋白质研究所进行，与A.S.Spirin教授合作，作为NIH编号：RC1AI078513。我们最近发现了一种新的细胞内信号转导途径，参与哺乳动物辐射敏感性的调节。这一途径由延伸因子2激酶(EEF2K)介导，eEF2K是全球蛋白质合成的关键调节因子。我们发现，在小鼠中灭活这一途径可以抵抗伽马辐射的致命影响，并对辐射诱导的毛发变白和辐射诱导的肠道细胞凋亡具有保护作用。父提案的目标是描述这一新的信号转导途径，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期抗凋亡蛋白的合成来刺激辐射诱导的细胞凋亡。我们进一步提供了eEF2K在翻译水平上调节抗凋亡蛋白表达的证据。这项建议的目的是确定eEF2磷酸化控制短期抗凋亡蛋白翻译的分子机制。这将通过使用A.S.Spirin和他的同事在蛋白质研究所开发的各种无细胞翻译系统和方法来实现。 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，蛋白质合成调节因子eEF2激酶的失活可以抵抗伽玛辐射的致命影响，也可以防止辐射诱导的毛发变白和辐射诱导的肠道细胞凋亡。在我们的初步实验中，我们发现eEF2激酶的敲除通过阻止短暂的抗凋亡蛋白的下调来保护细胞免受辐射诱导的凋亡。这项建议的目的是确定eEF2激酶控制短期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普什诺的俄罗斯科学院蛋白质研究所合作完成，与A.S.Spirin教授合作，作为NIH编号：RC1AI078513。

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.