ROLE OF CYTOSKELETON IN MAST CELL SIGNALING

肥大细胞能够对多种刺激做出反应， 抗原P物质和C3a IgE，由过敏性 个体与高亲和力IgE受体结合 （FcepsilonRI）在肥大细胞上发现， FcepsilonRI. 酪氨酸激酶的激活反过来导致 肌动蛋白聚合和更多的细胞骨架重排。 因此，肌动蛋白微丝之间存在积极的相互作用 和酪氨酸激酶。 该项目的总体目的是 研究酪氨酸激酶与 细胞骨架，并确定哪些激酶调节肌动蛋白 聚合，哪些激酶被调节 微丝 第一个具体目标是确定 酪氨酸激酶激活中的粘附和扩散 通过Fcephetri。 这将通过监测 几种酪氨酸激酶及其活性 非粘附与扩散中与细胞骨架的关联 通过FcepsilonRI激活的细胞。 肥大细胞， 缺乏单个酪氨酸激酶或表达显性 也将使用这些激酶的负突变体。 在 第二个目的，酪氨酸激酶Btk与 通过其PH结构域的微丝将被探索。 这 酪氨酸激酶也被认为参与两种抗原 诱导脱粒和肌动蛋白聚合。 这将是 使用表达显性阴性的转染肥大细胞 PH结构域的突变。 生物化学研究以及 共聚焦免疫荧光显微镜将被用于共同， 本地化实验 最终目标的目的是 研究肥大细胞对C3a的趋化反应。 因此 还涉及酪氨酸激酶驱动的肌动蛋白聚合。 C3a受体信号通路之间的串扰， 将探索FcepsilonRI信号通路。

Mast cells are able to respond to a wide variety of stimuli such as antigen, substance P, and C3a. IgE, produced by allergic individuals binds to the high affinity IgE receptor (FcepsilonRI) found on mast cells reactivated through FcepsilonRI. Activation of tyrosine kinases in turn leads to actin polymerization and more rearrangement of the cytoskeleton. Thus, there is an active interplay between actin microfilaments and tyrosine kinases. The overall purpose of th project is to investigate the relationship between tyrosine kinases and the cytoskeleton and to determine which kinases are regulating actin polymerization and which kinases are being regulated by microfilaments. The first specific aim is to determine the role of adhesion and spreading in the activation of tyrosine kinases through Fcepsilon RI. This will be accomplished by monitoring the activity of several tyrosine kinases as well as their association with the cytoskeleton in non-adherent versus spread cells activated through FcepsilonRI. Mast cells which are lacking individual tyrosine kinases or which express dominant negative mutants of these kinases will also be used. In the second aim, the association of the tyrosine kinase, Btk, with microfilaments through it's PH domain will be explored. This tyrosine kinase is also believed to be involved in both antigen induced degranulation and actin polymerization. This will be done using transfected mast cells expressing dominant negative mutations of the PH domain. Biochemical studies as well as confocal immunofluorescent microscopy will be used in co- localization experiments. The purpose of the final aim is to investigate the chemotactic response of mast cells to C3a. Thus also involves tyrosine kinase driven actin polymerization. Cross-talk between the C3a receptor signaling pathways and FcepsilonRI signaling pathways will be explored.