Eph and Lyn hyper-phosphorylation and CRMP interactions in AD"

Eph受体为心血管和神经元发育中的细胞迁移做出指导决定， 疾病和再生。Eph受体还与更高的大脑功能、记忆力和 学习。一种与阿尔茨海默氏症、帕金森氏症和其他神经性疾病有关的蛋白质 而损伤是一种与多种激酶相互作用的折叠蛋白反应介体蛋白(CRMP) 并随着激酶的激活而变得高度磷酸化。超级- 然后，磷酸化的CRMP破坏肌动蛋白和微管细胞骨架结构的形成，并 被认为阻碍了Aβ和Tau的清除。胞浆Lyn激酶是Fyn激酶的紧密同源物，是 已知与EphA4直接相互作用，在这里，我们第一次展示了EphA家族成员 EphB2与CRMP直接相互作用。类似于另一种制导和细胞迁移系统， Fyn-Plexin-CRMP复合体，Lyn-EphA4-CRMP结合可能与CDK5和CRMP形成复合体 GSK3CRMP和β-LYN的特征 相互作用的界面需要表征，因为它们将是潜在的生物标志物和目标 治疗性干预。该提案有两个主要目的。目的1)寻求建立体外培养的 EphA4和-B2胞内区不同激酶的磷酸化模式 CRMP的存在和不存在，并进一步验证细胞中复合体的形成。目标2) 相应的拟磷/磷缺陷突变对活性水平的影响 在这些Eph受体的胞内区和激酶上，将用纯化的蛋白在 体外培养。最终，利用这个项目的知识，抗体或复杂干扰肽可能 推动早期诊断和/或治疗的未来发展。

Eph receptors make guidance decisions for cell migration in cardiovascular and neuronal development, disease, and regeneration. Eph receptors are also involved with higher brain functions, memory and learning. A protein that has been associated with Alzheimer’s, Parkinson’s and other neuronal diseases and injuries is the Collapsin Response Mediator Protein (CRMP) which interacts with several kinases and becomes hyper-phosphorylated alongside increased activation of the kinases. The hyper- phosphorylated CRMP then disrupts the formation of actin and microtubule cytoskeletal structures and it thought to impede Aβ and tau clearance. Cytosolic Lyn kinase, a close homologue of Fyn kinase, is known to interact directly with EphA4 and here, for the first time, we show that an EphA family member and EphB2 directly interacts with CRMP. Analogous to another guidance and cell migration system, the Fyn-Plexin-CRMP complex, the Lyn-EphA4-CRMP association is likely to form a complex with Cdk5 and GSK3β kinases, each also involved in Alzheimer’s. The features of the Eph-CRMP and Eph-Lyn interacting interfaces need to be characterized, as they will be potential biomarkers and targets for therapeutic intervention. The proposal has two main aims. Aim 1) seeks to establish the in vitro phosphorylation patters of various kinases on the intracellular domains of EphA4 and –B2 in the presence and absence of CRMP and to further validate the formation of the complex in cells. Aim 2) The effect that the corresponding phosphomimetic/phospho-defective mutations have on the level of activity on these Eph receptor intracellular regions and of the kinases will be studied with purified proteins in vitro. Eventually, using the knowledge from this project, Antibodies or complex-disrupting-peptides may drive the future development of early detection diagnostics and/or therapeutics.