Functions of ARVCF and p120 catenin complexes

描述（由申请人提供）：连环蛋白对所有动物细胞和组织的生物学有贡献，在各种亚细胞区室中显示基本的胚胎和成年功能。除了在质膜上结合钙粘蛋白外，众所周知，B- catenin在细胞核中与TCF/LEF家族的转录因子相关，以转导对发育至关重要的发育Wnt信号，例如背轴形成、肢体模式和神经发生。最近，ARVCF和p120连环蛋白在质膜上的钙粘蛋白功能和细胞核内的其他潜在作用方面得到了关注。也许最突出的发现是p120调节对细胞运动和粘附至关重要的rho家族gtpase。显而易见的是，我们同样积累了ARVCF与RhoA功能偶联的证据，并在本提案中概述了我们的计划，以解决ARVCF（和p120）在调节RhoA家族GTPases中的发育作用。为了进一步了解ARVCF的功能，我们对相互作用的蛋白伴侣进行了酵母双杂交筛选。我们最近确定了三种新的蛋白质关联，通过体外和体内共沉淀方法进行了验证。我们将这三种蛋白质命名为CAP（连环蛋白相关蛋白），并期望每个CAP的物理关联反映了我们在本提案中提出的独特的功能相互作用。在我们的研究中，我们将采用非洲爪蟾胚胎系统，该系统允许外源构建物/试剂的容易引入（注射），并在外部环境中快速发育这种脊椎动物。我们将主要基于功能丧失（morpholino）、外源表达和拯救方法进行实验。

DESCRIPTION (provided by applicant): The catenin proteins contribute to the biology of all animal cells and tissues, displaying essential embryonic and adult functions within a variety of sub-cellular compartments. In addition to binding cadherin at the plasma membrane, B- catenin is well known to associate in the nucleus with transcription factors of the TCF/LEF family in transducing developmental Wnt signals crucial to development, for example, dorsal axis formation, limb patterning and neurogenesis. More recently, the ARVCF and p120 catenins have gained notice in the context of cadherin function at the plasma membrane and other potential roles within the nucleus. Perhaps the most prominent finding was that p120 modulates Rho-family GTPases crucial to cell motility and adhesion. As will be made evident, we have likewise accumulated evidence that ARVCF is functionally coupled to RhoA, and outline in this Proposal our plans to address the developmental role of ARVCF (and p120) in modulating Rho-family GTPases. To gain further insight of ARVCF function, we have conducted yeast two-hybrid screens for interacting protein partners. We recently identified three novel protein associations that were authenticated using in vitro and in vivo co precipitation approaches. We term these three proteins CAPs (Catenin Associated Protein), and expect that the physical association of each CAP reflects a distinct functional interaction which we propose to examine in the context of this Proposal. For our studies, we will employ the Xenopus embryo system that allows for the facile introduction (injection) of exogenous constructs/reagents and the rapid development of this vertebrate within an external environment. We will conduct experiments largely based upon loss-of-function (morpholino), exogenous expression and rescue approaches. Aims Addressed 1. What functional relationship exists between ARVCF (and Xp120) and each CAP? 2. What functional relationship exists between ARVCF (and p120) and Rho-family GTPases? Hypotheses Tested 1. CAPs modulate ARVCF (and p120) developmental functions 2. ARVCF (and p120) modulate the developmental functions of Rho-family GTPases