Non-equivalent roles of Drosophila Frizzled and Dfrizzled2 in embryonic wingless signal transduction.
Non-equivalent roles of Drosophila Frizzled and Dfrizzled2 in embryonic wingless signal transduction.
复制标题
果蝇卷曲和 Dfrizzled2 在胚胎无翅信号转导中的非等效作用。
DOI：
10.1016/s0960-9822(00)00697-7
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Bejsovec,A
中科院分区：
文献类型：
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作者：
Moline,MM;Dierick,HA;Southern,C;Bejsovec,A
高度保守的生长因子Wnt家族对于许多动物物种中产生胚胎模式是必需的[1]。在果蝇中，大多数Wnt介导的模式化是由一个单一的家族成员Wingless（Wg）通过其受体Frizzled（Fz）和DFrizzled 2（Dfz 2）发挥作用。在腹侧胚胎表皮，Wg信号产生两种不同的细胞命运的决定：生产不同的齿状突类型和规格的裸露角质层分隔齿状突带。wg的突变等位基因分别破坏这些细胞决定[2]，表明配体-受体亲和力的某些方面影响细胞命运决定，或者不同的受体复合物介导不同的细胞反应。在这里，我们报告说，Dfz 2的过度表达，而不是Fz，拯救突变表型的wgPE 2，一个等位基因，产生的齿多样性，但没有裸露的角质层。只有在Wg配体过量存在的条件下，Fz才能取代Dfz 2。ThewgPE 2突变体表型也敏感的糖胺聚糖的剂量，这表明，突变体配体被排除在受体复合物时，蛋白聚糖的存在。我们得出结论，野生型Wg信号需要配体和Dfz 2-蛋白聚糖受体复合物之间的有效相互作用，以促进裸角质层细胞的命运。
The highly conserved Wnt family of growth factors is essential for generating embryonic pattern in many animal species [1]. In the fruit flyDrosophila, most Wnt-mediated patterning is performed by a single family member, Wingless (Wg), acting through its receptors Frizzled (Fz) and DFrizzled2 (Dfz2). In the ventral embryonic epidermis, Wg signaling generates two different cell-fate decisions: the production of diverse denticle types and the specification of naked cuticle separating the denticle belts. Mutant alleles ofwgdisrupt these cellular decisions separately [2], suggesting that some aspect of ligand–receptor affinity influences cell-fate decisions, or that different receptor complexes mediate the distinct cellular responses. Here, we report that overexpression of Dfz2, but not Fz, rescues the mutant phenotype ofwgPE2, an allele that produces denticle diversity but no naked cuticle. Fz was able to substitute for Dfz2 only under conditions where the Wg ligand was present in excess. ThewgPE2mutant phenotype was also sensitive to the dosage of glycosaminoglycans, suggesting that the mutant ligand is excluded from the receptor complex when proteoglycans are present. We conclude that wild-type Wg signaling requires efficient interaction between ligand and the Dfz2–proteoglycan receptor complex to promote the naked cuticle cell fate.