The endoplasmic reticulum (ER) as a key regulator of metabolism

我们的实验室研究控制细胞内膜之间接触的蛋白质。这些触点传递各种信号并控制许多细胞功能。内质网（ER）形成最著名的细胞内接触。我们的研究计划旨在了解这些功能。在这个建议中，我们调查如何ER接触决定细胞代谢和细胞的能量输出，通过ERA-ER接触（MERC）。这种生命的关键结构由两个细胞器之间的脂质和Ca 2+离子流控制。我们实验室正在进行的研究表明，这种流动是由传感器蛋白控制的。 这些传感器的上游是Rab蛋白，其确定接触位点的蛋白质组成。这些GTP酶利用与称为GTP的高能化合物的可逆结合来富集或去除MERC中的传感器蛋白。我们的初步结果表明，Rab 32介导的传感器蛋白的本地化MERC响应ER衍生的氧化应激。根据我们的观察，我们假设ER应激和Rab介导的MERC重塑共同决定细胞代谢。 在此NSERC应用中，我们将测试这一假设，并通过引入酵母S来研究这些功能的保存程度。cerevisiae作为我们实验的新模型系统。我们的项目旨在回答几个关键问题。Rab GTP酶是否响应一个共同的上游信号，如果是，是哪一个？这些信号如何控制Rabs和传感器蛋白？我们提出以下具体目标：1。GTP酶如何响应ER衍生的蛋白质折叠应激？我们将分析Rabs的活性是否在ER蛋白折叠应激时发生变化。我们将测试这些变化是否依赖于Rab的翻译后修饰或与鸟嘌呤核苷酸交换因子（GEF）的相互作用。2. MERC膜如何将ER GT3活性传递给线粒体？我们将分析影响ER的GTP酶如何改变MERC关键特性（蛋白质组，Ca 2+处理和脂质组）并控制线粒体代谢。3.内质网代谢需要向线粒体的传递是保守的吗？我们将分析酵母的保护我们的观察和筛选新的代谢调节MERC。我希望这个提议能将联合收割机酵母和动物模型系统结合起来，建立一个基于ER相关GT3运输蛋白的代谢网络。我们的NSERC资助的研究计划的继续是必不可少的，以保持一流的培训和出版成功的高素质的人员（HQP）在我们的实验室的所有级别。

Our laboratory investigates proteins that control contacts between intracellular membranes. These contacts communicate a variety of signals and control many cellular functions. The endoplasmic reticulum (ER) forms the best-known intracellular contacts. Our research program aims to understand the functions of these. In this proposal, we investigate how ER contacts determine cellular metabolism and the cellular energy output via mitochondria-ER contacts (MERCs). This key structure for life is controlled by a flow of lipids and Ca2+ ions between the two organelles. Ongoing research from our lab shows this flow is controlled by sensor proteins. Upstream of these sensors are Rab proteins that determine the protein composition of the contact site. These GTPases use the reversible binding to a high energy compound called GTP to either enrich or remove sensor proteins from MERCs. Our preliminary results show that Rab32-mediated localization of sensor proteins to MERCs responds to ER-derived oxidative stress. From our observations, we hypothesize that ER stress and Rab-mediated MERC remodeling cooperate to determine cellular metabolism. In this NSERC application we will test this hypothesis and also investigate the extent of conservation of these functions by introducing the yeast S. cerevisiae as a new model system for our experiments. Our project aims to answer several key questions. Do Rab GTPases respond to a common upstream signal and if so which one? How do such signals control Rabs and the sensor proteins? We propose the following specific aims: 1. How do GTPases respond to ER-derived protein folding stress? We will analyze whether the activity of Rabs changes upon ER protein folding stress. We will test whether these changes depend on Rab post-translational modifications or interactions with guanine nucleotide exchange factors (GEFs). 2. How do MERC membranes transmit ER GTPase activity to mitochondria? We will analyze how ER-influencing GTPases change MERC key properties (proteome, Ca2+ handling and lipidome) and control mitochondria metabolism. 3. Is the transmission of ER metabolic needs to mitochondria conserved? We will analyze yeast for the conservation of our observations and to screen for novel metabolic regulators of MERCs. I expect this proposal to combine yeast and animal model systems to establish a metabolic network based on ER-associated GTPase trafficking proteins. The continuation of our NSERC-funded research program is essential to maintain the first-class training and publication success of high-quality personnel (HQP) of all levels in our lab.