A Caenorhabditis elegans type I TGF beta receptor can function in the absence of type II kinase to promote larval development.
A Caenorhabditis elegans type I TGF beta receptor can function in the absence of type II kinase to promote larval development.
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发表时间：
2000-08
期刊：
影响因子：
4.6
通讯作者：
C. V. Gunther;L. Georgi;D. Riddle
中科院分区：
文献类型：
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作者：
C. V. Gunther;L. Georgi;D. Riddle
daf-4基因编码秀丽隐杆线虫中的II型骨形态发生蛋白受体，该受体调节dauer幼虫的形成、身体大小和雄性尾巴模式。推测的I型受体配偶体的调节dauer幼虫的形成是dauer-1。对这些受体激活机制的遗传学测试表明，在没有α-4激酶活性的情况下，β-1可以发出信号。daf-1突变增强daf-4无效背景下dauer形成，而daf-1过表达部分挽救了daf-4突变体。单独的β 1受体不能完全补偿β 4受体活性的丧失，这表明非道尔发育通常是由两种受体的活性引起的。在II型激酶不存在的情况下，β-l信号传导在I型受体家族中是独特的。由于daf-1的起源接近I型/II型分歧，这种活性可能是进化的残余，或者它可能是线虫进化的创新。daf-1和daf-4启动子均介导绿色荧光蛋白在神经系统中的表达，表明DAF-1/DAF-4受体复合物可激活神经元信号传导途径。信号从一个强大的α-1/α-4受体复合物或一个较弱的α-1受体单独可以提供幼虫更精确的控制的dauer/nondauer决定在一系列的环境条件。
The daf-4 gene encodes a type II bone morphogenetic protein receptor in Caenorhabditis elegans that regulates dauer larva formation, body size and male tail patterning. The putative type I receptor partner for DAF-4 in regulating dauer larva formation is DAF-1. Genetic tests of the mechanism of activation of these receptors show that DAF-1 can signal in the absence of DAF-4 kinase activity. A daf-1 mutation enhances dauer formation in a daf-4 null background, whereas overexpression of daf-1 partially rescues a daf-4 mutant. DAF-1 alone cannot fully compensate for the loss of DAF-4 activity, indicating that nondauer development normally results from the activities of both receptors. DAF-1 signaling in the absence of a type II kinase is unique in the type I receptor family. The activity may be an evolutionary remnant, owing to daf-1's origin near the type I/type II divergence, or it may be an innovation that evolved in nematodes. daf-1 and daf-4 promoters both mediated expression of green fluorescent protein in the nervous system, indicating that a DAF-1/DAF-4 receptor complex may activate a neuronal signaling pathway. Signaling from a strong DAF-1/DAF-4 receptor complex or a weaker DAF-1 receptor alone may provide larvae with more precise control of the dauer/nondauer decision in a range of environmental conditions.