Cargo sorting during endocytic recycling

内吞回收过程中的货物分类

• 批准号: 7487545
• 负责人: VICTOR W HSU
• 金额: $ 29.87万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7487545
• 关键词: ADP-ribosylation factor 6; Binding; Biological Assay; Biological Models; Capsid Proteins; Cells; Complex; Cytosol; Endosomes; Event; Gap Junctions; In Vitro; Integrins; Ligands; Liposomes; Low Density Lipoprotein Receptor; Mediating; Membrane; Nexus (resin cement); Nutrient; Phosphorylation; Phosphotransferases; Play; Process; Protein Overexpression; Protein Sortings; Proteins; Recycling; Role; Signal Transduction; Sorting - Cell Movement; System; Testing; Transferrin Receptor; Transport Process; base; cell motility; computerized data processing; in vivo; mutant; novel; receptor; reconstitution; uptake

Endocytic recycling is critical for many cellular events, including the recycling of important nutrient receptors, such as the transferrin receptor and the low-density lipoprotein receptor, for reiterative rounds of ligand uptake, and also the redistribution of integrins from the retracting edges to the leading edge of cells to mediate their motility. Despite these many documented important roles, how proteins are sorted during endocytic recycling, a process that critically regulates their function, remains poorly understood. In preliminary studies, we have identified ACAP1 to function in the sorting of cargo proteins that exemplify constitutive and regulated recycling at the recycling endosome, with its phosphorylation providing an explanation for how it is able to participate in both processes. Moreover, we have found thatoverexpression of ACAP1 induces the coating of endosomes. Thus, in Aim 1, we will provide a more definitive test for whether ACAP1 functions as a coat protein using a reconstitution system that generates transport carriers from the recycling endosome, followed by approaches which will either prove that ACAP1 alone functions as a coat protein or that it functions in conjunction with other proteins as part of coat complex. In Aim 2, because the critical nexus in regulated transport involves the signaling process interfacing with the transport process, we will identify kinase(s) predicted to directly phosphorylate ACAP1. In Aim 3, as we have identified sorting signals recognized by ACAP1 for constitutive recycling, we will also identify sorting signal(s) recognized by ACAP1 for regulated recycling, using integrin betal as the model system. This finding will then enable us to further elucidate how ACAP1 is able to participate in both constitutive and regulated recycling. Moreover, the identification of recycling sorting signal(s) in integrin betal will allow us to test more definitively whether integrin recycling plays a critical role in cell migration, and thereby demonstrating that a better understanding of endocytic recycling has important implications to understanding other cellular events.

内吞回收对于许多细胞事件至关重要，包括重要营养受体的回收， 例如转铁蛋白受体和低密度脂蛋白受体，用于重复的配体回合 吸收，以及整合素从缩回边缘到细胞前缘的重新分布 调解他们的运动能力。尽管有许多记录了重要角色，但如何在 批判性调节其功能的过程的内吞回收仍然很少理解。在 初步研究，我们已经确定了ACAP1在体现的货物蛋白的分类中起作用 回收内体的组成型和调节的回收利用，其磷酸化提供了 说明它如何参与两个过程。而且，我们发现了这种表达 ACAP1的诱导内体涂层。因此，在AIM 1中，我们将为 ACAP1是否使用生成运输载体的重构系统充当外套蛋白 从回收的内体中，接下来的方法将证明ACAP1仅起作用 外套蛋白或与其他蛋白一起起作用，作为外套复合物的一部分。在AIM 2中， 因为受管制运输中的临界联系涉及与传输的信号传导过程接口 过程，我们将确定预测将直接磷酸化ACAP1的激酶。在AIM 3中，就像我们有 确定了由ACAP1识别的用于本构回收的排序信号，我们还将确定分类信号 由ACAP1识别用于调节的回收，使用整合蛋白betal作为模型系统。这一发现将 然后使我们能够进一步阐明ACAP1如何能够参与本构和监管 回收。此外，整合蛋白betal中回收分选信号的识别将使我们能够进行更多测试 明确地，整联蛋白回收是否在细胞迁移中起关键作用，从而表明 对内吞回收的更好理解对理解其他细胞事件具有重要意义。