Chemical mapping of the PPIase interactome in C. elegans - development of a systems biology toolbox

秀丽线虫是一种只有959个细胞的自由生活的圆形蠕虫。它的基因组产生19,000种蛋白质(相比之下，人类基因组产生约25,000种蛋白质)。我们将向蠕虫中引入化学物质，并观察它们的反应，特别是它们蛋白质的变化。小分子可能是荷尔蒙、药物或毒素，可以对生物系统产生深远的影响。变化通常是由于小分子(配体)直接与特定的“靶蛋白”结合，并阻止其发挥正常功能所致。这些类型的分子被称为抑制剂。目前，我们对特定蛋白质与配体结合时在细胞中的‘连锁’效应知之甚少。我们想要设计与线虫中特定蛋白质家族结合的分子，然后改变它们的行为。我们将监测这种化学物质对整个蠕虫的影响，并确定其他哪些蛋白质受到影响。在这个项目中，我们将只看一个蛋白质家族，免疫亲和素，我们对它有相当多的背景知识。超过20种不同的蛋白质属于这个家族。我们知道它们可以起到酶的作用，也可以帮助蛋白质折叠。我们已经合成了抑制这些免疫亲和素的新类型的分子，并在线虫中显示出生物活性。我们已经在这些抑制分子中的一些分子上贴上了荧光标签，这样我们就可以(使用光学显微镜)看到这些分子被蠕虫占据的位置。我们将看到蠕虫中的蛋白质在接触到这些抑制物配体时会发生什么变化。通过测试将在该项目中制造的数百种不同的抑制剂，我们将识别具有特定生物效应的分子。线虫体内的许多蛋白质与哺乳动物中的蛋白质相似，因此我们还将了解这些化学物质在动物系统中的影响。我们来自蠕虫的数据可能会在基因调控、发育生物学和药物发现等领域对人类和兽医生物学产生重大影响。

Caenorhabditis elegans (C. elegans) is a free living round worm comprising only 959 cells. Its genome produces 19,000 proteins (compared with some 25,000 from the human genome). We will introduce chemicals into the worms and look to see how they respond, particularly in terms of changes in their proteins. Small molecules which might be hormones, drugs or toxins can have profound effects on biological systems. Changes are usually caused by the small molecules (ligands) binding directly to a particular 'target protein' and stopping it from performing its normal function. These types of molecules are known as inhibitors. Currently we have a very poor understanding of the 'knock-on' effects in the cell when a given protein is bound to a ligand. We want to design molecules that bind to particular families of proteins in C.elegans and then modify their behaviour. We will monitor the effect of the chemical on the whole worm and identify which of the other proteins are affected. In this project we will only look at one family of proteins, the immunophilins, for which we have considerable background knowledge. Over 20 different proteins belong to this family. We know that they can act as enzymes and also help protein folding. We have synthesised new classes of molecules that inhibit these immunophilins and also show biological activity in the C.elegans. We have already put fluorescent-labels on some of these inhibitor molecules so that we see (using an optical microscope) where the molecules are taken up by the worm. We will see how proteins in worm change when they are exposed to these inhibitor ligands. By testing the many hundreds of different inhibitors that will be made in this project, we will identify molecules that have specific biological effects. Many of the proteins in C. elegans are similar to those in mammals, and so we will also learn about the effect of these chemicals in animal systems. Our data from worms could have a major impact on human and veterinary biology in areas like gene regulation, developmental biology, and drug discovery.