Molecular genetics of Drosophila Wnt signaling

果蝇 Wnt 信号传导的分子遗传学

基本信息

批准号：
7115873
负责人：
MARCEL WEHRLI
金额：
$ 25.8万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-09-02 至 2009-08-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The long-term goal of the proposed research is to understand how Wnt signals regulate normal development and cancer. The immediate goal is to refine our understanding of how Wnt signals are transduced by studying Arrow, a single pass transmembrane protein recently identified by the PI. Arrow, together with members of the Frizzled (Fz) family, is a co-receptor for the fly Wnt, Wingless (Wg). A fusion of the Arrow cytoplasmic tail to the Fz2 carboxy-terminus (Fz2-Arr[i]) recapitulates the proximity normally generated during receptor activation by the Wnt ligand, demonstrating that Arrow and Fz2 function as co-receptors. Fz2-Arr[i] functions as an activated receptor that is necessary and sufficient to generate ligand- independent signaling. In the first aim, structure/function analyses of this chimeric receptor, which is locked in the signaling conformation, will be performed to identify domains that may be required for assembly of intracellular complexes that transduce Wnt signals from the membrane to the nucleus. The second aim will identify Arrow-interacting proteins by (a) Immunoprecipitating and micro sequencing Arrow-associated proteins from fly embryos, and (b) a novel and highly sensitive yeast two-hybrid system that allows the isolation of components interacting with a membrane protein, the activated receptor. Fly genetics will then be used to identify the in vivo function of Arrow- interacting proteins. The third aim is based on our finding that Axin, a far downstream component of the Wnt cascade, directly interacts with the Arrow cytoplasmic domain (and therefore the activated receptor). This interaction was unexpected since Axin was previously shown to bind and negatively regulate Armadillo (fly B-catenin), the final cytoplasmic Wg/Wnt pathway component. This raises the possibility that Arrow not only functions as a receptor subunit but also regulates the final step in signaling by binding Axin, thereby freeing Armadillo to enter the nucleus and signal. This hypothesis will be tested by analyzing Wnt signaling in transgenic flies made to express mutant Axin proteins that discriminate between binding to Arrow or Armadillo. Collectively, these studies will provide insights into a signaling pathway that is required for normal development of all species and insights into cancers due to deregulation of these processes.

描述（由申请人提供）：拟议研究的长期目标是了解 Wnt 信号如何调节正常发育和癌症。近期目标是通过研究 Arrow（PI 最近鉴定的单次跨膜蛋白）来加深我们对 Wnt 信号如何转导的理解。 Arrow 与 Frizzled (Fz) 家族的成员一起，是果蝇 Wnt、Wingless (Wg) 的共同受体。 Arrow 细胞质尾部与 Fz2 羧基末端 (Fz2-Arr[i]) 的融合概括了 Wnt 配体激活受体期间通常产生的邻近性，证明了 Arrow 和 Fz2 作为共受体发挥作用。 Fz2-Arr[i] 作为激活的受体发挥作用，它对于产生配体非依赖性信号传导是必要且充分的。第一个目标是对这种锁定在信号传导构象中的嵌合受体进行结构/功能分析，以鉴定组装将 Wnt 信号从膜转导到细胞核的细胞内复合物可能所需的结构域。第二个目标将通过以下方式鉴定 Arrow 相互作用蛋白：(a) 对果蝇胚胎中的 Arrow 相关蛋白进行免疫沉淀和微测序，以及 (b) 一种新型且高度灵敏的酵母双杂交系统，该系统可以分离与膜蛋白相互作用的成分，激活的受体。然后，蝇遗传学将用于鉴定 Arrow 相互作用蛋白的体内功能。第三个目标是基于我们的发现，即 Wnt 级联的远下游成分 Axin 直接与 Arrow 胞质结构域（以及激活的受体）相互作用。这种相互作用是出乎意料的，因为 Axin 先前已被证明可以结合并负向调节犰狳（蝇 B-连环蛋白），即细胞质 Wg/Wnt 通路的最终成分。这提出了一种可能性，即Arrow不仅充当受体亚基，而且还通过结合Axin来调节信号传导的最后一步，从而释放犰狳进入细胞核并发出信号。该假设将通过分析转基因果蝇中的 Wnt 信号传导来测试，该转基因果蝇表达突变轴蛋白，可区分与 Arrow 或犰狳的结合。总的来说，这些研究将提供对信号通路所需的见解。由于这些过程的放松管制，所有物种的正常发育和对癌症的了解。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

In vivo analysis in Drosophila reveals differential requirements of contact residues in Axin for interactions with GSK3beta or beta-catenin.

果蝇体内分析揭示了 Axin 中接触残基与 GSK3beta 或 β-catenin 相互作用的不同需求。

DOI：
10.1016/j.ydbio.2009.10.016
发表时间：
2010
期刊：
Developmental biology
影响因子：
2.7
作者：
Kremer,SusanA;Erdeniz,Naz;Peterson-Nedry,Wynne;Swanson,ElizabethA;Wehrli,Marcel
通讯作者：
Wehrli,Marcel