Identification of a novel PDZ domain containing protein, fzip, as an interacting partner of frizzled

鉴定出一种包含蛋白质 fzip 的新型 PDZ 结构域，作为卷曲蛋白的相互作用伙伴

基本信息

批准号：
11680711
负责人：
YAO Ryoji
金额：
$ 2.43万
依托单位：
Japanese Foundation for Cancer Research
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680711/
关键词：
Wnt signaling Frizzled Golgi apparatus Acrosome Infertility ノックアウトマウス精子形成 PDZドメイン

项目摘要

The frizzled gene family encodes serpentine membrane receptors, which are proposed to be cognate receptors for Wnt molecules. Although Wnt molecules are suggested to regulate several signaling pathways, the precise mechanisms are largely unknown. We initiated the search for frizzled interacting proteins, since no direct downstream molecules for frizzled gene family have been identified in any organisms.By using yeast two-hybrid system, we have identified a novel frizzled interacting protein, fzip-1. Fzip-1 contains two coiled-coil motifs and one PDZ domain which is involved in the binding to the S/T-X-V-COOH motif of frizzled. Interestingly, although fzip-1 is associated with the Golgi apparatus, it translocated to the plasma membrane when frizzled was co-expressed, suggesting that fzip-1 may play a role to translocate frizzled proteins from Golgi apparatus to plasma membrane.Since Wnt signaling pathways are implicated in many aspects of developmental process as well as tumorgenesis, we generated fzip-1 deficient mice by gene targeting. Fzip-1 homozygous mutant mice were viable and exhibited no visible phenotype. However, in breeding experiments, it became apparent that male homozygous mutant mice were consistently infertile. Although no overt abnormality was observed in the initiation of spermatogenesis, most of the spermatozoa in epididymis had aberrant head morphology and lacked acrosome. In spermatids, significant accumulation of fzip-1 was observed in perinuclear regions. Taken together, these results indicate that fzip-1 is required for the vesicle transport from the Golgi apparatus, and that it may play a role in the membrane transport of frizzled.

卷曲基因家族编码蛇形膜受体，该受体被认为是 Wnt 分子的同源受体。尽管 Wnt 分子被认为可以调节多种信号通路，但其确切机制很大程度上尚不清楚。由于在任何生物体中都没有鉴定出卷曲基因家族的直接下游分子，我们开始寻找卷曲相互作用蛋白。通过使用酵母双杂交系统，我们鉴定了一种新型卷曲相互作用蛋白，fzip-1。 Fzip-1 包含两个卷曲螺旋基序和一个 PDZ 结构域，该结构域参与与卷曲的 S/T-X-V-COOH 基序的结合。有趣的是，虽然fzip-1与高尔基体相关，但当卷曲蛋白共表达时，它易位到质膜，这表明fzip-1可能发挥卷曲蛋白从高尔基体易位到质膜的作用。与发育过程以及肿瘤发生的许多方面有关，我们通过基因靶向产生了 fzip-1 缺陷小鼠。 Fzip-1 纯合突变小鼠能够存活并且没有表现出可见的表型。然而，在育种实验中，很明显雄性纯合突变小鼠始终不育。尽管在精子发生的起始阶段没有观察到明显的异常，但附睾中的大多数精子具有异常的头部形态并且缺乏顶体。在精子细胞中，在核周区域观察到 fzip-1 的显着积累。总而言之，这些结果表明 fzip-1 是从高尔基体进行囊泡运输所必需的，并且它可能在卷曲的膜运输中发挥作用。