Drosophila Stardust is a partner of Crumbs in the control of epithelial cell polarity
Drosophila Stardust is a partner of Crumbs in the control of epithelial cell polarity
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DOI：
10.1038/414638a
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发表时间：
2001-12-06
期刊：
影响因子：
64.8
通讯作者：
Knust, E
中科院分区：
文献类型：
--
作者：
Bachmann, A;Schneider, M;Knust, E
上皮细胞的极化结构取决于细胞连接和其他膜相关蛋白复合物的高度刻板分布。在果蝇胚胎的上皮细胞中，三个不同的区域细分为外侧质膜。最顶端的是次根尖复合体（SAC）。紧随其后的是附着小带（ZA），再往下，是隔结(1)。SAC的一个核心成分是跨膜蛋白屑，其细胞质结构域将pdz -蛋白disc Lost招募到复合物中（2,3）。缺乏碎屑或功能相关基因星尘的细胞不能组织连续的ZA并维持细胞极性（4-6）。在这里，我们展示了星尘提供了SAC的重要组成部分。星尘蛋白与碎屑共定位，并结合到其细胞质尾部的羧基末端氨基酸上。我们在这里介绍两种不同的Stardust蛋白：一种MAGUK蛋白，具有PDZ结构域、SH3结构域和鸟苷酸激酶结构域；第二异构体仅包含鸟苷酸激酶结构域。Stardust蛋白作为SAC的结构成分和可能的调控成分，是控制上皮细胞极性的关键因素。
The polarized architecture of epithelial cells depends on the highly stereotypic distribution of cellular junctions and other membrane-associated protein complexes. In epithelial cells of the Drosophila embryo, three distinct domains subdivide the lateral plasma membrane. The most apical one comprises the subapical complex (SAC). It is followed by the zonula adherens (ZA) and, further basally, by the septate junction(1). A core component of the SAC is the transmembrane protein Crumbs, the cytoplasmic domain of which recruits the PDZ-protein Discs Lost into the complex(2,3). Cells lacking crumbs or the functionally related gene stardust fail to organize a continuous ZA and to maintain cell polarity(4-6). Here we show that stardust provides an essential component of the SAC. Stardust proteins colocalize with Crumbs and bind to the carboxy-terminal amino acids of its cytoplasmic tail. We introduce two different Stardust proteins here: one MAGUK protein, characterized by a PDZ domain, an SH3 domain and a guanylate kinase domain; and a second isoform comprising only the guanylate kinase domain. The Stardust proteins represent versatile candidates as structural and possibly regulatory constituents of the SAC, a crucial element in the control of epithelial cell polarity.