Development of a High-Throughput Lipid-Protein Assay and the Discovery of a Necrosis Mediator

Lipid-protein interactions play a critical role in cellular signaling by recruiting both intra- and extracellular proteins to the partnering membranes. Many studies have been performed to identify new lipid binding proteins and small molecule inhibitors that can interfere with the membrane binding of proteins. Although there are many assays developed to study lipid-protein interactions, there is no universal, sensitive, and robust high-throughput screening method available. Here, we have developed a high-throughput membrane binding assay based on fluorescence quenching. Sorting Nexin 21 (SNX21) is one of the SNX family proteins that contains the PX domain. Although the exact physiological roles of many SNX proteins remain unclear, it is hypothesized that most SNX proteins are involved in membrane trafficking via the lipid-binding PX domain. Here, we present new evidences indicating the possible involvement of SNX21 in necrotic cell death.