Coordinating Adhesion Receptors in Axon Growth

协调轴突生长中的粘附受体

• 批准号: 6752813
• 负责人: JACK E LILIEN
• 金额: $ 36.88万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6752813
• 关键词: SDS polyacrylamide gel electrophoresis; axon; biological signal transduction; cadherins; chick embryo; embryo /fetus culture; enzyme linked immunosorbent assay; green fluorescent proteins; immunoprecipitation; neural cell adhesion molecules; neuronal guidance; phosphorylation; polymerase chain reaction; protein structure function; protein tyrosine kinase; receptor binding; retinal ganglion; western blottings

DESCRIPTION (provided by applicant): Retinal ganglion cell axons are guided along their trajectories during development by many different systems of adhesion, attraction and repulsion. Proper axon growth and guidance requires integration in the growth cone of information from many distinct receptor systems. Our long term goals are to identify the environmental cues and signaling paths that integrate adhesion receptor function during development of axons in the neural retina. N-cadherin and beta1-integrins are two of the adhesion systems that play decisive roles in retinal axon elongation and guidance. We have discovered a pathway which coordinately regulates N-cadherin and beta1-integrin function during axon outgrowth. When cells or growth cones contact the chondroitin sulfate proteoglycan neurocan, both N-cadherin and beta1-integrin function is lost. This coordinate loss of function correlates with translocation of the non-receptor tyrosine kinase Fer from its usual association in the cadherin complex of proteins to the complex of proteins associated with the cytoplasmic domain of beta1-integrin. Our hypothesis is that coordinate regulation of cadherin and integrin plays an important role in preventing ganglion cell axons from straying from their appropriate path. The goal of this application is to define the role of Fer in cadherin and integrin function and to examine the role of this pathway in the development of retina ganglion cell axons. Aims 1 and 2 define the role of Fer in the function of cadherin and integrin respectively. We will identify effectors whose presence or phosphorylation is altered in the presence and absence of Fer and how these altered components regulate function. Aim 3 defines the regulatory site in the cadherin cytoplasmic domain responsible for transducing the signal initiating the shuttling of Fer. This will be accomplished by deletion and mutagenesis of N-cadherin, as well as functional comparison of other Type I and II cadherins present in the neural retina for the ability to participate in cross-regulation between cadherin and integrin. In Aim 4 we will determine the role of this cross regulatory circuit in development of retinal ganglion cell axon projections through inhibition of the binding of neurocan, the extracellular signal that initiates coordinate regulation, and through the use of cell permeable peptides to perturb cadherin and/or integrin function.

描述（由申请人提供）：视网膜神经节细胞轴突在发育过程中通过许多不同的粘附，吸引力和排斥系统沿其轨迹引导。适当的轴突生长和指导需要在许多不同受体系统的信息的生长锥中整合。我们的长期目标是确定在神经视网膜中轴突发育过程中整合粘附受体功能的环境线索和信号通路。 N-钙粘蛋白和β1-积聚蛋白是在视网膜轴突伸长和指导中起决定性作用的两个粘附系统。我们发现了一条途径，该途径在轴突生长过程中协调调节N-钙粘蛋白和beta1-紧密蛋白功能。当细胞或生长锥接触硫酸软骨素蛋白聚糖神经can时，N-钙粘着蛋白和β1-整合蛋白功能都会丧失。该功能的这种坐标损失与非受体酪氨酸激酶的转运相关，其在蛋白质的钙粘蛋白复合物中的通常关联到与beta1-整合素的细胞质结构域相关的蛋白质络合物。我们的假设是，坐标的钙粘蛋白和整合素的调节在防止神经节细胞轴突偏离其适当路径方面起着重要作用。该应用的目的是定义FER在钙粘蛋白和整联蛋白功能中的作用，并检查该途径在视网膜神经节细胞轴突发展中的作用。目标1和2分别定义了FER在钙粘蛋白和整联蛋白的功能中的作用。我们将确定在存在和不存在FER的情况下改变的效应因素以及这些改变的组件如何调节功能。 AIM 3定义了钙粘着蛋白的细胞质结构域中的调节位点，负责转导FER穿梭的信号。这将通过N-钙粘着蛋白的缺失和诱变以及神经视网膜中存在的其他I和II型钙粘蛋白的功能比较来实现，以便能够参与钙粘着蛋白和整合素之间的交叉调节。在AIM 4中，我们将通过抑制神经can的结合来确定该跨调节电路在视网膜神经节细胞轴突投影开发中的作用，这是启动坐标调节的细胞外信号，并通过使用可渗透的肽来扰动Cadherin和/或整联蛋白的功能。