Authors: J.A. MacKay, M.K. Pastuszka, P. Shi, J. Dhandhukia
Affilation: University of Southern California, United States
Pages: 239 - 241
Keywords: elastin-like polypeptide, clathrin mediated endocytosysis, protein polymer, nanoparticle, microdomain
Biology is unparalleled in the replication of complex structures with diverse functions on the molecular and cellular scale. By using biological materials to assemble structures, process information, and harness energy, the emerging field of synthetic biology may bridge this gap between current technology and that needed to study and intervene in disease. To explore functional nano-biomaterials, our work focuses on genetically-engineered protein polymers. While there are multiple ways to control protein activity (gene deletion, siRNA, drugs, etc.), few approaches are rapid and reversible. Elastin-like polypeptides (ELPs) are protein polymers, of the sequence (VPGXG)l that have potential applications as reversible switches. ELPs self-associate above a transition temperature, which is a function of the identity of X and l. Utilizing the phase behavior of ELPs, we hypothesized that the intracellular machinery of clathrin-mediated endocytosis can be reversibly sequestered, thus switching off internalization. To control clathrin-mediated endocytosis, ELPs were fused to the N-terminus of the clathrin light chain. When co-expressed with a receptor that follows clathrin-mediated endocytosis, the ELP fusion protein permits normal endocytosis. In contrast, receptor internalization was blocked above the transition temperature. With study, this technology may become a tool for the controlled manipulation of biological signaling and trafficking pathways.