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)被认为是人类已知的毒性最强的化学物质之一。它的毒性作用包括卟啉症、一种严重消耗综合征、化生、致畸和免疫抑制。芳香烃受体(AHR)对这种毒性是必不可少的。在缺乏配体的情况下，AHR存在于与Hsp90的二聚体和ARAS的单体结合的胞浆中。ARA9与FK506结合蛋白有序列相似性。ARA9的作用是维持AHR的稳定性和适当的细胞区隔。它实现这些功能的方法尚不清楚。此外，ARA9在AHR的次级信号转导和配体毒性中的作用尚未确定。最后，目前尚不清楚ARA9是否可以将其他细胞蛋白招募到AHR胞浆复合体中，或者影响其他细胞信号级联反应。初步数据表明，ARA9可能与已知的各种信号通路的介体相互作用。这种相互作用导致了以下假设：ARA9通过将其他蛋白质招募到AHR胞浆复合体并直接影响其他细胞信号级联来影响二恶英介导的信号转导。为了解决这一假设，提出了三个具体的目标：1)映射ARA9和其他细胞信号分子的相互作用表面。2)利用蛋白质组学工具鉴定AHR信号网络的新成员。3)利用一种新的磷酸蛋白质组固相富集技术，确定TCDD处理细胞中磷酸化模式的变化。在完成这些目标后，研究人员将通过确定其他细胞信号靶点来扩大对TCDD毒性的理解。此外，它们将直接与这一信号级联的重大翻译后修饰相关。最后，这项工作将建立一个潜在的二次毒性机制，因为它与TCDD接触有关。

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.