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。人类拥有的许多与疾病相关的基因中的一个突变可能会增加罹患疾病的风险。但是，这些疾病相关基因中的一个发生突变并不总是意味着一个人会患上这种疾病。这种情况在帕金森病(PD)中就会发生，帕金森病最常见的遗传因素是名为GBA的基因突变。这个基因编码的蛋白质是葡萄糖脑苷酶(GCase)，它能将葡萄糖从一种糖修饰的脂肪分子中分离出来，这种脂肪分子在大脑中特别丰富。尽管携带这种突变的人更有可能更早地患上帕金森病，并有更严重的症状，但并不是所有携带GBA基因突变的人都会患上帕金森病。这导致人们假设，还有其他基因与GBA相互作用，增加或减少患帕金森病的机会。众所周知，在其他疾病中也会发生这种情况，在这些疾病中，各种基因的突变可以通过所谓的遗传相互作用来影响患上特定疾病的可能性。因此，人们对识别与GBA相互作用的基因，然后了解它们可能如何影响GCase的功能非常感兴趣。事实上，人们对GCase在细胞内是如何调控的知之甚少，但这些基本信息可能有助于更好地理解这种蛋白质的调控。在这项提议中，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，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，使其能够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，通过最先进的筛选方法来识别与GBA相互作用的基因。通过这种方式，我们将对这些基因如何调控GCase有一个基本的了解。制药公司可以利用这些知识来创造新的药物，使加拿大和世界各地的帕金森氏症患者受益。由于帕金森病是第二常见的神经退行性疾病，目前还没有减缓帕金森病进展的治疗方法，因此非常需要有新的见解，可以利用这些见解来创造新的药物。

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.