Kwok Trevor C Y, Ricker Nicole, Fraser Regina, Chan Allen W, Burns Andrew, Stanley Elise F, McCourt Peter, Cutler Sean R, Roy Peter J
Department of Medical Genetics and Microbiology, and The Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada.
Nature. 2006 May 4;441(7089):91-5. doi: 10.1038/nature04657.
Small-molecule inhibitors of protein function are powerful tools for biological analysis and can lead to the development of new drugs. However, a major bottleneck in generating useful small-molecule tools is target identification. Here we show that Caenorhabditis elegans can provide a platform for both the discovery of new bioactive compounds and target identification. We screened 14,100 small molecules for bioactivity in wild-type worms and identified 308 compounds that induce a variety of phenotypes. One compound that we named nemadipine-A induces marked defects in morphology and egg-laying. Nemadipine-A resembles a class of widely prescribed anti-hypertension drugs called the 1,4-dihydropyridines (DHPs) that antagonize the alpha1-subunit of L-type calcium channels. Through a genetic suppressor screen, we identified egl-19 as the sole candidate target of nemadipine-A, a conclusion that is supported by several additional lines of evidence. egl-19 encodes the only L-type calcium channel alpha1-subunit in the C. elegans genome. We show that nemadipine-A can also antagonize vertebrate L-type calcium channels, demonstrating that worms and vertebrates share the orthologous protein target. Conversely, FDA-approved DHPs fail to elicit robust phenotypes, making nemadipine-A a unique tool to screen for genetic interactions with this important class of drugs. Finally, we demonstrate the utility of nemadipine-A by using it to reveal redundancy among three calcium channels in the egg-laying circuit. Our study demonstrates that C. elegans enables rapid identification of new small-molecule tools and their targets.
蛋白质功能的小分子抑制剂是生物学分析的有力工具，并且能够推动新药的研发。然而，开发有用的小分子工具的一个主要瓶颈是靶点识别。在此我们表明，秀丽隐杆线虫能够为发现新的生物活性化合物和靶点识别提供一个平台。我们在野生型线虫中筛选了14100种小分子的生物活性，鉴定出308种可诱导多种表型的化合物。我们命名为nemadipine-A的一种化合物在形态和产卵方面诱导出明显缺陷。Nemadipine-A类似于一类广泛使用的抗高血压药物，即1,4-二氢吡啶类（DHPs），它们拮抗L型钙通道的α1亚基。通过遗传抑制子筛选，我们鉴定出egl-19是nemadipine-A的唯一候选靶点，这一结论得到了其他几条证据的支持。egl-19编码秀丽隐杆线虫基因组中唯一的L型钙通道α1亚基。我们表明nemadipine-A也能拮抗脊椎动物的L型钙通道，证明线虫和脊椎动物共享直系同源蛋白靶点。相反，美国食品药品监督管理局批准的DHPs未能引发明显的表型，这使得nemadipine-A成为筛选与这类重要药物的遗传相互作用的独特工具。最后，我们通过使用nemadipine-A揭示产卵回路中三个钙通道之间的冗余性，证明了它的实用性。我们的研究表明，秀丽隐杆线虫能够快速鉴定新的小分子工具及其靶点。
