Giráldez Antonio J, Copley Richard R, Cohen Stephen M
European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117 Heidelberg, Germany.
Dev Cell. 2002 May;2(5):667-76. doi: 10.1016/s1534-5807(02)00180-6.
The secreted signaling protein Wingless acts as a morphogen to pattern the imaginal discs of Drosophila. Here we report identification of a secreted repressor of Wingless activity, which we call Notum. Loss of Notum function leads to increased Wingless activity by altering the shape of the Wingless protein gradient. When overexpressed, Notum blocks Wingless activity. Notum encodes a member of the alpha/beta-hydrolase superfamily, with similarity to pectin acetylesterases. We present evidence that Notum influences Wingless protein distribution by modifying the heparan sulfate proteoglycans Dally-like and Dally. High levels of Wingless signaling induce Notum expression. Thus, Wingless contributes to shaping its own gradient by regulating expression of a protein that modifies its interaction with cell surface proteoglycans.
分泌型信号蛋白无翅（Wingless）作为一种形态发生素，为果蝇的成虫盘定型。在此，我们报告了一种无翅活性分泌型抑制因子的鉴定，我们将其命名为Notum。Notum功能缺失通过改变无翅蛋白梯度的形状导致无翅活性增加。当Notum过表达时，它会阻断无翅活性。Notum编码α/β水解酶超家族的一个成员，与果胶乙酰酯酶相似。我们提供的证据表明，Notum通过修饰硫酸乙酰肝素蛋白聚糖类Dally样蛋白（Dally-like）和Dally来影响无翅蛋白的分布。高水平的无翅信号诱导Notum表达。因此，无翅通过调节一种修饰其与细胞表面蛋白聚糖相互作用的蛋白质的表达，来塑造自身的梯度。
