Design of Membrane-Associated Signaling Modulators

描述（由申请人提供）：Ras蛋白是膜相关蛋白，其通过充当许多受体偶联信号传导途径的分子“开-关”开关来调节细胞活化。在约25%的致癌转化中发现Ras蛋白突变导致活化状态。某些Ras蛋白还与小窝蛋白-1相互作用，小窝蛋白-1是一种胆固醇结合膜蛋白，通过与受体偶联信号级联连接的特定脂质微结构域（脂筏）调节细胞运输。这两种类型的蛋白质都含有脂质和膜结合结构域，用于其膜相关功能。本申请将集中于Ras蛋白模拟物的开发，这些蛋白模拟物能够通过膜转移和膜结合来调节Ras信号通路。Ras模拟物的关键设计是具有或不具有充当转运蛋白的脂肪酰化链的新型膜可渗透α/ε-肽树枝化基元。我们的近期目标包括开发一种基于串联连接的新型合成平台，用于制备由检测探针、膜渗透性树枝状分子、肽货物或脂质组成的试剂，以促进我们实验中的测定和机理研究。开发一种有效的靶向调节细胞内递送大分子的策略代表了我们应用的长期目标。为了实现我们的目标，该应用程序将使用化学和生物工具。具体目标#1将开发用于制备Ras蛋白模拟物的试剂和合成平台。目的#2和#3将评价可溶性膜渗透性和膜相关Ras模拟物以抑制Ras效应物及其在脂筏中的缔合。目的#4将比较Ras模拟物通过内体途径的递送机制。

DESCRIPTION (provided by applicant): Ras proteins are membrane-associated proteins that modulate cell activation by acting as a molecular "on-off" switch of many receptor-coupled signaling pathways. Mutations of Ras protein leading to an activated state are found in about 25 % of oncogenic transformation. Certain Ras proteins also interacts with caveolin-1, a cholesterol-binding membrane protein that regulates cellular trafficking through a specific lipid microdomain (lipid raft) linked to receptorcoupled signal cascades. Both types of proteins contain lipids and membrane-binding domains for their membrane-associated functions. This application will focus on the development of Ras protein mimetics that are capable of membrane-tanslocation and membrane-association to modulate Ras signaling pathways. The key design of the Ras mimetics is a novel membrane permeable alpha/epsilon-peptide dendron with or without fatty acylated chains that function as transportants. Our immediate goals include the development of a novel synthetic platform based on tandem ligation for preparing reagents consisting of detection probes, membranepermeable dendrons, peptide cargoes or lipids to facilitate assays and mechanistic study in our experiments. The development of an effective strategy for targeting regulated intracellular delivery of macromolecules represents a long-term objective of our application. To achieve our goals, this application will use both chemical and biological tools. Specific Aim #1 will develop reagents and a synthetic platform for preparing Ras protein mimetics. Aims #2 and #3 will evaluate soluble membrane-permeable and membrane-associated Ras mimetics to inhibit Ras effectors and their association in lipid rafts. Aim #4 will compare the delivery mechanisms of Ras mimetics through endosomal pathway.