Molecular mechanisms of membrane protein homeostasis at the Golgi

项目摘要/摘要 高尔基复合体在真核细胞的分泌和内吞运输中起着重要的作用 并且是糖偶联物(糖蛋白和糖脂)生物合成的关键，而糖蛋白和糖脂是 生活。高尔基体驻留蛋白，如糖基转移酶和糖核苷酸转运体，正是 通过循环机制在高尔基体堆叠中分布，以抵消持续的囊泡流动 运输。这些机制的功能障碍，或它们被病毒和毒素劫持，已知有 对人类健康造成严重后果，导致先天性糖基化障碍、癌症和 免疫功能障碍。 驻留在不同高尔基间隔中的膜蛋白被很好地诠释；然而，机制-- 大多数高尔基体蛋白质如何被选择进行循环利用，或者这些过程是如何被调控的 人们对此了解甚少。我的实验室感兴趣的是揭示这些基本的机制 结合遗传学、流式细胞术、成像的多方面方法在体外实现高尔基体动平衡 重组和蛋白质组学。在初步结果中，我们发现了新的跨膜化合物。 协调回收高尔基体酶的特定亚组。我们的发现为我们打开了 审问新球员并剖析对维持高尔基人身份和功能至关重要的机制。 在接下来的五年里，我们的目标是(1)确定不同高尔基体所需的新型回收受体 划分和建立高尔基内部回收网络的系统图，(2)确定如何 跨膜受体与它们的货物结合，以及(3)定义疾病的新功能-- 高尔基体中溶质运输和蛋白质循环中的相关膜转运体。合并后的 我们的实验结果将阐明多种循环途径如何维持正常的高尔基体功能， 以及这种动态平衡在人类疾病中是如何被破坏的。

Project summary/Abstract The Golgi complex plays a prominent role in secretory and endocytic trafficking in eukaryotic cells and is key to the biosynthesis of glycoconjugates (glycoproteins and glycolipids) that are essential for life. Golgi resident proteins, such as glycosyltransferases and sugar nucleotide transporters, are precisely distributed across the Golgi stacks by recycling mechanisms that counteract the flow of ongoing vesicular transport. Dysfunction in these mechanisms, or their hijacking by viruses and toxins, is known to have serious consequences for human health, leading to congenital disorders of glycosylation, cancers, and immune dysfunction. Membrane proteins residing in various Golgi compartments are well annotated; however, the mecha- nistic basis of how most Golgi proteins are selected for recycling, or how these processes are regulated are poorly understood. My lab is interested in uncovering these fundamental mechanisms governing Golgi homeostasis using a multifaceted approach combining genetics, flow-cytometry, imaging, in vitro reconstitution, and proteomics. In preliminary results, we have identified novel transmembrane compo- nents orchestrating recycling of specific subsets of Golgi enzymes. Our findings have opened doors for interrogating new players and dissecting the mechanisms critical to maintain Golgi identity and function. Over the next five years, our goals are to (1) identify novel recycling receptors required at different Golgi compartments and establish a systematic map of the intra-Golgi recycling network, (2) determine how the transmembrane receptors engage with their cargos, and (3) define the novel functions of a disease- associated membrane transporter in solute transport and protein recycling in the Golgi. The combined results of our experiments will elucidate how multiple recycling pathways sustain normal Golgi function, and how this homeostasis is disrupted in human disease.