Live long and prosper: probing the mechanism of a transporter family linked to lifespan extension, protection from diabetes and obesity, and cancer.

人类的寿命比历史上任何时候都要长，但这是有代价的，包括糖尿病和肥胖症等与年龄相关的代谢性疾病病例的增加。这些慢性病越来越普遍；目前在英国，每2分钟就有1人被诊断出患有糖尿病，三分之一的人肥胖，这是英国第二大可预防的癌症原因。这些疾病改变了患者的生活，也给卫生服务带来了巨大的负担。柠檬酸是人体正常新陈代谢的关键营养素。通过破坏主要的柠檬酸运输蛋白Indy的功能来降低柠檬酸盐的细胞浓度，可以延长寿命(因此而得名我还没有死)，预防糖尿病和肥胖，并防止肝癌细胞增殖。因此，Indy转运蛋白在预防和治疗这些疾病方面是非常有希望的药物靶点。Indy转运蛋白的许多机制细节仍不清楚，包括它们如何与底物和抑制剂相互作用，以及膜环境如何影响这些相互作用。这个项目将使用最先进的计算和实验方法弥合我们知识中的这些差距。基于细菌Indy同系物VcINDY的晶体结构，我们已经确定了一个迄今尚未表征的底物结合位点，它是抑制剂结合的主要目标。此外，我们还鉴定了15种与VcINDY相互作用的化学成分多样的化合物。在这个项目中，我们将使用原子模拟来预测蛋白质：抑制物相互作用以及脂质双层组成如何影响底物/抑制物结合。我们将使用一套尖端技术来测试这些预测，包括：基于蛋白质脂质体的体外转运分析和脂质纳米颗粒中的高分辨率底物结合分析。这些发现将促进我们对这些迷人而重要的转运蛋白的基本了解，并为开发Indy蛋白抑制剂提供一个跳板。

Humans are living longer than ever before in our history, but this comes at a cost, including an amplification in cases of age-related metabolic diseases like diabetes and obesity. These chronic illnesses are increasingly prevalent; currently 1 person is diagnosed with diabetes every 2 minutes in the UK, and 1/3 of people >35 are obese, which is the UK's 2nd biggest preventable cause of cancer. These illnesses have life-changing effects on patients and are also an enormous burden on the health services. Citrate is a key nutrient for normal metabolism in humans. Reducing the cellular concentration of citrate by disrupting the function of the maincitrate transport protein, INDY, extends life span (hence the name which stands for I'm not dead yet), protects against diabetes and obesity, and prevents liver cancer cell proliferation. Therefore, INDY transporters are very promising drug targets in the prevention and treatment of these diseases. Many mechanistic details of INDY transporters remain unclear, including how they interact with substrates and inhibitors, and how the membrane environment influences these interactions. This project will bridge these gaps in our knowledge using state-of-the-art computational and experimental approaches. Based on the crystal structure of a bacterial INDY homologue, VcINDY, we have identified a hitherto uncharacterised substrate binding site that is a prime target for inhibitor binding. In addition, we have identified ~15 chemically diverse compounds that interact with VcINDY. In this project, we will use atomistic simulations to predict protein:inhibitor interactions and how the lipid bilayer composition affects substrate/inhibitor binding. We will test these predictions using a suite of cutting-edge techniques, including; proteoliposome-based in vitro transport assays and high-resolution substrate binding assays in lipid nanoparticles. These findings will advance our fundamental understanding of these fascinating and important transporters and provide a springboard for the development of INDY protein inhibitors.