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

一般来说，每个基因都有两个拷贝。人类拥有的许多疾病相关基因之一的突变会增加患疾病的风险。但是，这些疾病相关基因中的一个突变并不总是意味着一个人会患上这种疾病。已知这种情况发生在帕金森病（PD）中，其中导致PD的最常见遗传因素是称为GBA的基因突变。该基因编码蛋白质葡萄糖脑苷脂酶（GCase），该蛋白质将葡萄糖从糖修饰的脂肪分子中切断，该脂肪分子在大脑中特别丰富。尽管具有这种突变的人更有可能在早期患上PD，并且症状更严重，但并非所有具有GBA基因突变的人都会患上PD。这导致人们假设有其他基因与GBA相互作用，并增加或减少患PD的机会。这是已知的发生在其他疾病中，其中各种基因的突变可以通过所谓的遗传相互作用影响发展特定疾病的可能性。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，人们对GCase在细胞内是如何调节的知之甚少，但这些基本信息可以帮助更好地理解这种蛋白质的调节。在这项提案中，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，这些工具能够直接观察活细胞中GCase蛋白的活性。此外，我们还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，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PD患者受益。由于PD是第二常见的神经退行性疾病，并且没有减缓PD进展的治疗方法，因此非常需要可以用于开发新药的新见解。

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.