Autoproteolysis and feedback in a protease cascade directing Drosophila dorsal-ventral cell fate
Autoproteolysis and feedback in a protease cascade directing Drosophila dorsal-ventral cell fate
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DOI：
10.1093/emboj/20.10.2387
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发表时间：
2001-05-15
期刊：
影响因子：
11.4
通讯作者：
DeLotto, R
中科院分区：
文献类型：
--
作者：
Dissing, M;Giordano, H;DeLotto, R
三个丝氨酸蛋白酶酶原，胃泌素缺陷型（GD），蛇（Snk）和复活节（Ea），和神经生长因子样生长因子配体前体，Spaetzle，需要在果蝇胚胎发育过程中的背腹细胞命运的规格。已经提出蛋白酶在称为卵周间隙的细胞外隔室内的顺序激活级联中起作用。我们使用异源共表达系统研究了这四种蛋白质之间的生化相互作用。结果表明，这三种蛋白酶确实在顺序激活级联中起作用，GD变得活跃并启动级联，并且GD和Snk之间的相互作用足以使GD自我蛋白水解切割。Ea的蛋白水解活性形式在不同位置切割GD，揭示了途径中的生化反馈。GD和Snk都与肝素-琼脂糖凝胶结合，提供了管道定义的腹侧前模式和蛋白酶级联之间的联系。我们的研究结果表明，在其中启动的级联模型是由抑制救济，和空间调节的活动是由于与硫酸化蛋白聚糖的相互作用。
Three serine protease zymogens, Gastrulation defective (GD), Snake (Snk) and Easter (Ea), and a nerve growth factor-like growth factor ligand precursor, Spaetzle, are required for specification of dorsal-ventral cell fate during Drosophila embryogenesis. The proteases have been proposed to function in a sequential activation cascade within the extracellular compartment called the perivitelline space. We examined biochemical interactions between these four proteins using a heterologous co-expression system. The results indicate that the three proteases do function in a sequential activation cascade, that GD becomes active and initiates the cascade and that interaction between GD and Snk is sufficient for GD to cleave itself autoproteolytically. The proteolytically active form of Ea cleaves GD at a different position, revealing biochemical feedback in the pathway. Both GD and Snk bind to heparin-Sepharose, providing a link between the pipe-defined ventral prepattern and the protease cascade. Our results suggest a model of the cascade in which initiation is by relief from inhibition, and spatial regulation of activity is due to interaction with sulfated proteoglycans.