Dr Christopher Mulligan- University of Kent
Prof Jonathan Essex – University of Southampton
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 main
citrate 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.