Like a fence that encloses a backyard, all of the body's cells are surrounded by membranes. Each membrane has its own complement of membrane proteins, which perform critical functions like letting things in and out of the cell, and keeping the inside of the cell informed of what's happening on the outside. Mark Dumont, Ph.D., professor of Biochemistry and Biophysics and Pediatrics, says that more than half of the drugs on the market today target membrane proteins.
Despite their importance, the structures and mechanisms that determine how these proteins work are not very well understood. In a recent study in Science, Dumont and collaborators at the University of Virginia and the Hauptman-Woodward Institute in Buffalo describe the structure of a particular membrane protein called Ste24p that is involved in cutting up other proteins in yeast. If there's a defect in this protein, yeast can't mate.
The obvious next question is, how is yeast's inability to reproduce relevant to people? It turns out, the human equivalent of the protein Ste24p, when mutated, causes progeria -- a premature aging disorder in which children develop hair loss, joint ailments, and heart disease, which they typically die of in their mid-teens. Dumont says that better understanding how this protein works -- in yeast and in people -- will help scientists to design a drug or other treatment for this devastating disorder and learn more about the human aging process.
Nadia Fedoriw, a technician in Dumont's lab, grows yeast used for protein production
Dumont is a senior investigator of the Membrane Protein Structural Biology Consortium, one of nine NIH-funded centers across the country that are trying to solve the structures of membrane proteins. He worked with Kathleen Clark and Nadia Fedoriw from Pediatrics and Sara Connelly from Biochemistry and Biophysics on the study.