Proteomics and the dioxin signaling network

描述（由申请人提供） 2，3，7，8-四氯二苯并对二恶英（TCDD）是目前已知的毒性最强的化学物质之一，其毒性作用包括卟啉症（一种严重的消耗综合征）、化生、致畸和免疫抑制。芳香烃受体（AHR）是这种毒性的关键。在没有配体的情况下，AHR被发现在结合到Hsp 90的二聚体和ARAS的单体的胞质溶胶中。ARA 9与FK 506结合蛋白具有序列相似性。ARA 9用于维持AHR的稳定性和适当的细胞区室化。它实现这些功能的方法是未知的。此外，ARA 9在AHR配体的次级信号传导和毒性中发挥的作用尚未确定。 最后，ARA 9是否可以募集其他细胞蛋白质到AHR胞质复合物或影响其他细胞信号级联尚不清楚。 初步数据表明，ARA 9可能与各种信号通路的已知介质相互作用。这种相互作用导致了以下假设：ARA 9通过招募其他蛋白质到AHR胞质复合物并直接影响其他细胞信号级联来影响二恶英介导的信号传导。为了解决这一假设，提出了三个具体的目标：1）映射ARA 9和其他细胞信号分子的相互作用表面。2)使用蛋白质组学工具来识别AHR信号网络的新成员。3)使用新型磷酸化蛋白质组学固相富集技术鉴定TCDD处理细胞中磷酸化模式的变化。 在完成这些目标后，研究人员将通过识别其他细胞信号靶点来扩展对TCDD毒性的理解。此外，它们将直接与该信号级联的显著翻译后修饰相关。 最后，这项工作将建立一个潜在的机制，二次毒性，因为它涉及到TCDD暴露。

DESCRIPTION (provided by applicant) 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is characterized as one of the most toxic chemicals known to man. Its toxic effects include porphyria, a severe wasting syndrome, metaplasia, teratogenesis and immune suppression. The aryl hydrocarbon receptor (AHR) is essential to this toxicity. In the absence of ligand, the AHR is found in the cytosol bound to a dimmer of Hsp90 and a monomer of ARAS. ARA9 shares sequence similarities to FK506 binding proteins. ARA9 acts to maintain stability and proper cellular compartmentalization of the AHR. The method by which it fulfills these functions is unknown. In addition, what role ARA9 plays in secondary signaling and toxicity of ligands for the AHR has not been determined. Finally, it is not known whether ARA9 can recruit other cellular proteins to the AHR cytosolic complex or act to influence other cellular signaling cascades. Preliminary data suggests that ARA9 may interact with a known mediator of various signaling pathways. This interaction has lead to the following hypothesis: ARA9 influences dioxin mediated signaling by recruiting other proteins to the AHR cytosolic complex and directly influencing other cellular signaling cascades. To address this hypothesis, three specific aims are proposed: 1) Map the interaction surfaces of ARA9 and other cellular signaling molecules. 2) Use proteomic tools to identify new members of the AHR signaling network. 3) Identify changes in phosphorylation patterns in TCDD treated cells using a novel phosphoproteomic solid phase enrichment technology. Upon completion of these aims, the investigators will have extended the understanding of TCDD toxicity by identifying other cellular targets for signaling. In addition, they will have directly related a significant post-translational modification to this signaling cascade. Finally, this work will establish a potential mechanism for secondary toxicity as it relates to TCDD exposure.