Functional analysis of alkylglycerol monooxygenase; an unexpected modulator of Wnt signalling and embryogenesis

总体情况是：胚胎要想正常发育，或者成人要正常运作，细胞之间需要相互沟通。这种交流告诉细胞它们应该做什么。Wnt信号通路是一种细胞通讯系统，在告诉细胞在胚胎发育过程中如何表现方面发挥着重要作用。Wnt信号受损会导致出生缺陷，并导致包括癌症在内的许多成人疾病。因此，重要的是我们要了解Wnt途径是如何工作的，这样我们才能发现控制它的方法，并有可能找到治疗疾病的新方法。Wnt途径中的蛋白质可以被细胞修饰，以控制它们的功能。几乎Wnt信号通路中的每一步都受到小脂类的附着或去除的调节。然而，尽管这些脂质修饰很重要，但我们对它们是如何发生的以及它们如何控制Wnt信号的了解仍然非常有限。这在一定程度上是因为很难找到进行这些修改的基因。我们最近发现，一种名为Amgo的基因是Wnt信号的调节器，是胚胎心脏正常发育所必需的。Amgo编码已知的唯一能切割特定类型脂类(称为乙醚类脂)的酶。我们也有初步证据表明，agmo在头部、大脑和肌肉的发育中发挥着重要作用。此外，在超过25名agmo突变的人类患者中，发现了神经、心脏、肌肉和面部异常的组合。然而，我们仍然对agmo如何发挥作用，或者如何需要乙醚类脂来形成胚胎知之甚少。在这个项目中，我们将研究agmo在Wnt信号和发育中的作用。在目标1中，我们将确定agmo是否真的是头部、大脑和肌肉正常发育所必需的？我们将通过降低蝌蚪和小鸡胚胎中的agmo水平来实现这一点，并使用最先进的成像和分子生物学分析来查看这些结构的发育是否发生了变化。在目标2中，我们将研究agmo如何影响Wnt信号通路。特别是，我们将使用一系列的分子实验来发现在途径中需要agmo的步骤，以及它调节Wnt信号的机制。最后，在目标3中，我们将精确地测量agmo耗竭是如何影响胚胎脂质代谢的。一旦我们确定了agmo耗竭青蛙的途径哪里出了问题，我们将测试是否可以纠正这个新陈代谢问题，以防止Wnt信号问题和出生缺陷。同时，这些实验将揭示Wnt途径的一个新的、强大的调节器是如何工作的。我们认为，我们的发现有可能改变我们对Wnt途径的理解，我们希望为基础和治疗研究开辟新的途径。

The big picture: for an embryo to develop normally, or an adult to function correctly, cells need to communicate with each other. This communication tells cells what they should do. The Wnt signalling pathway is a cellular communication system that plays important roles in telling cells how to behave during development of an embryo. Impaired Wnt signalling causes birth defects and contributes to numerous adult diseases, including cancers. As such, it is important we understand how the Wnt pathway works so that we can discover ways to control it and potentially find new ways to treat disease.Proteins in the Wnt pathway can be modified by cells to control how they function. Almost every step in the Wnt signalling pathway is regulated by the attachment or removal of small lipids. However, despite the importance of these lipid modifications, our understanding of how they occur and how they control Wnt signalling remains very limited. In part this is because it is difficult to find the genes making these modifications. We recently discovered that a gene named amgo, which encodes the only enzyme known to cut a particular type of lipids (called ether lipids), is a regulator of Wnt signalling and is required for normal development of the embryonic heart. We also have preliminary evidence that agmo plays an important role in development of the head, brain and muscles. Furthermore, combinations of neural, cardiac, muscle and facial abnormalities have been identified in over 25 human patients with mutations in agmo. However, we still know very little about how agmo functions, or how ether lipids are needed to form an embryo. In this project we will investigate the role of agmo in Wnt signalling and development.In Objective 1, we will determine whether agmo is really required for normal development of the head, brain and muscles? We will do this by decreasing agmo levels in tadpoles and chick embryos and using state of the art imaging and molecular biology assays to see if development of these structures is altered.In Objective 2, we will investigate how agmo affects the Wnt signalling pathway. In particular, we will use a series of molecular experiments to discover the step in the pathway where agmo is needed, and the mechanism by which it regulates Wnt signalling.Finally, in Objective 3 we will precisely measure how agmo depletion is affecting embryonic lipid metabolism. Once we have identified where the pathway goes wrong in agmo depleted frogs, we will then test whether we can correct this metabolic problem to prevent the Wnt signalling problems and birth defects.Together, these experiments will reveal how a new and powerful regulator of the Wnt pathway works. We think that our discoveries have the potential to transform our understanding of the Wnt pathway, and we hope to open up new avenues of basic and therapeutic research.