Adhesion dynamics in Drosophila border cell migration

果蝇边缘细胞迁移的粘附动力学

• 批准号: 7010356
• 负责人: Denise J. Montell
• 金额: $ 31.49万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7010356
• 关键词: Drosophilidae; actins; biological signal transduction; cadherins; cell adhesion; cell migration; gene expression; genetic models; guanine nucleotide binding protein; guanosinetriphosphatase activating protein; protein structure function

DESCRIPTION (provided by applicant): Cell migration is a fascinating feature of embryonic development, and improperly regulated cell migration contributes to birth defects and tumor metastasis. We have developed a simple model system for a forward genetic approach to the study of cell motility in vivo, the migration of a subset of follicle cells, known as border cells, in the Drosophila ovary. We have established that multiple extracellular signals regulate their movement. 1) a global steroid hormone signal, ecdysone, acting through the ecdysone receptor and a transcriptional coactivator called Taiman; 2) a highly localized cytokine signal, which activates the JAK/STAT pathway; and 3) several growth factors, which signal through the EGFR and PVR receptor tyrosine kinases to guide the cells to their destination. In addition we have studied a variety of cytoskeleton-associated proteins and cell adhesion molecules that function in border cell migration. This proposal explores the mechanisms by which cell adhesion is dynamically regulated in migrating border cells, an important aspect of cell motility that is not well understood for any cell type. We propose three specific aims. The first is to investigate the mechanisms that govern trafficking and stability of E-cadherin, a homophilic cell-cell adhesion molecule that is required in border cells and in the cells upon which they migrate. To test whether E-cadherin is turned over more rapidly in border cells than in non-migrating follicle cells, we will employ a previously characterized variant of the red fluorescent protein that changes color over time, fused to E-cadherin. We will investigate whether EGFR and PVR signaling destabilizes cell adhesion by phosphorylation of specific tyrosine residues on beta-catenin/Armadillo. We will also determine whether endocytosis is important for regulating cell surface E-cadherin in migrating border cells. We will test whether Drosophila moesin contributes to E-cadherin dynamics. And we will investigate the mechanisms by which Myosin VI contributes to E-cadherin dynamics in border cells. In the second specific aim we propose to investigate in detail the mechanisms by which RhoGAP93B contributes to border cell migration by studying its biochemical activity, its expression pattern, subcellular localization, lethal phenotype and its regulation. Finally we propose to study a putative downstream target of Rho in border cells, rhophilin by characterizing the mutant phenotype, epistasis analysis with Rho and by identifying and characterizing interacting proteins.

描述（由申请人提供）：细胞迁移是胚胎发育的引人入胜的特征，不当调节的细胞迁移会导致先天缺陷和肿瘤转移。我们已经开发了一种简单的模型系统，用于一种向前遗传学方法研究体内细胞运动的研究，这是果蝇卵巢中卵泡细胞（称为边界细胞）的一部分的迁移。我们已经确定，多个细胞外信号调节其运动。 1）通过ecdysone受体作用的全球类固醇激素信号Ecdysone和称为Taiman的转录共激活因子； 2）高度局部的细胞因子信号，该信号激活JAK/STAT途径； 3）几个生长因子通过EGFR和PVR受体酪氨酸激酶发出信号，以引导细胞进入其目的地。此外，我们研究了在边界细胞迁移中起作用的各种细胞骨架相关蛋白和细胞粘附分子。该提案探讨了细胞粘附在迁移的边界细胞中动态调节的机制，这是细胞运动的重要方面，对于任何细胞类型而言尚未很好地理解。我们提出了三个具体目标。首先是研究E-钙粘着蛋白的运输和稳定性的机制，E-钙粘蛋白是一种同粒细胞 - 细胞粘附分子，在边界细胞和它们迁移的细胞中所需的机制。为了测试边界细胞中的E-钙粘蛋白是否比非迁移卵泡细胞更快地翻转过来，我们将采用先前表征的红色荧光蛋白变体，该变体随着时间的推移而变化，融合到E-钙粘着蛋白。我们将研究EGFR和PVR信号传导是否通过在β-catenin/armadillo上的特定酪氨酸残基的磷酸化来破坏细胞粘附。我们还将确定内吞作用对于调节迁移边界细胞中细胞表面e-钙粘着蛋白是否重要。我们将测试果蝇是否有助于E-钙粘蛋白动力学。我们将研究肌球蛋白VI对边界细胞中的E-钙粘蛋白动力学有助于的机制。在第二个具体目的中，我们建议通过研究其生化活性，其表达模式，亚细胞定位，致命的表型及其调节来详细研究rhoGAP93B促进边界细胞迁移的机制。最后，我们建议通过表征突变体表型，用Rho来表征突变体表型，并通过识别和表征相互作用的蛋白质来研究Rho的假定下游靶标，这是Rhophilin。