Membrane protein folding: from simplistic models to the biological reality of co-translation

Every time a cell builds a membrane protein, it folds the chain while it is still being assembled—a process this project will finally track in real time. Most protein-folding research has studied proteins that were first fully made, then deliberately unfolded in a test tube. That bears little resemblance to what happens inside a living cell. For helical membrane proteins—a large and medically important class—folding occurs co-translationally: the ribosome threads the growing chain into the lipid bilayer, and the structure takes shape as the chain lengthens. This project will develop kinetic methods to watch that process unfold, using bacterial inner membrane transporters as a model system. It asks three concrete questions: when during elongation does structure appear, how does folding speed couple to translation rate, and how does the lipid environment modulate the process. This is fundamental science. It will not produce a drug or a diagnostic tomorrow. But membrane proteins are the targets of roughly half of all modern medicines. Understanding how they fold correctly—and, by extension, how they misfold in disease—could eventually reshape how we think about protein-misfolding disorders, antibiotic resistance, and the design of membrane-protein-based therapies. Past work on protein folding in solution has already informed treatments for cystic fibrosis and Alzheimer’s; this work extends that logic into the far more complex, and biologically realistic, co-translational regime.