Chemical biology probes to monitor glucocerebrosidase activity in fixed cells and tissues

人们通常每个基因都有两个拷贝。人类拥有许多与疾病相关的基因，其中一种基因的突变会增加患疾病的风险。但是，这些与疾病相关的基因发生突变并不总是意味着一个人会患上这种疾病。这种情况已知发生在帕金森病（PD）中，其中最常见的遗传因素是GBA基因的突变。这种基因编码蛋白质葡萄糖脑苷酶（GCase），它能从糖修饰的脂肪分子中切断葡萄糖，这种脂肪分子在大脑中尤其丰富。尽管有这种突变的人更有可能在早期患上帕金森病，并且有更严重的症状，但并非所有有GBA基因突变的人都会患上帕金森病。这导致人们猜测还有其他基因与GBA相互作用，从而增加或减少患帕金森病的几率。这种情况在其他疾病中也会发生，在这些疾病中，各种基因的突变可以通过所谓的基因相互作用影响患上某种特定疾病的可能性。因此，人们对鉴定与GBA相互作用的基因并了解它们如何影响GCase功能非常感兴趣。事实上，我们对GCase在细胞内是如何调控的知之甚少，但这些基本信息可以帮助我们更好地理解这种蛋白质的调控。在这个提议中，我们的目标是利用我们在化学生物学工具方面的最新进展，使我们能够直接观察活细胞中GCase蛋白的活性。此外，我们将化学合成新的探针分子，以新的方式测量这种酶的活性。最终，我们将使用这些化学工具来识别与GBA相互作用的基因，并使用最先进的筛选方法。通过这种方式，我们将对这些基因如何调节GCase有一个基本的了解。制药公司可以利用这些知识来开发新药，使加拿大和世界各地的PD患者受益。因为帕金森病是第二常见的神经退行性疾病，并且没有治疗方法可以减缓帕金森病的进展，所以非常需要新的见解来开发新药。

People generally have two copies of each gene. A mutation in one of the many disease-related genes that humans have can increase the risk of developing disease. But having a mutation in one of these disease-related genes does not always mean that a person will get the disease. Such a case is known to occur in Parkinson Disease (PD) where the most common hereditary factor contributing to PD are mutations in the gene called GBA. This gene codes for the protein glucocerebrosidase (GCase) that cuts glucose off from a sugar-modified fat molecule that is especially abundant in brain. Even though people with this mutation are much more likely to get PD earlier on and have more severe symptoms, not all people who have a mutation in the GBA gene do develop PD. This has led people to hypothesize that there are other genes that interact with GBA and either increase or decrease the chance of getting PD. This is known to occur for other diseases where mutations in various genes can influence the likelihood of developing a specific disease through what is known as a genetic interaction. There is accordingly high interest in identifying genes that interact with GBA and then understanding how they might influence GCase function. Indeed, little is known about how GCase is regulated within cells but such fundamental information could help better understand the regulation of this protein. In this proposal we aim to exploit our recent advances in chemical biology tools that enable directly watching the activity of GCase protein in living cells. In addition, we will chemically synthesize new probe molecules that enable measuring the activity of this enzyme in new ways. Ultimately, we will use these chemical tools to identify genes that interact with GBA using state of the art screening methods. In this way we will get a basic understanding of how such genes could regulate GCase. Such knowledge could be exploited by pharmaceutical companies to create new drugs that could benefit PD patients in Canada and around the world. Because PD is the second most common neurodegenerative disease, and there is no treatment that slows progression of PD, there is a great need to new insights that could be exploited to create new medicines.