The winners of the Nobel Prize in Physiology or Medicine (from left), James E. Rothman, Randy W. Schekman and Thomas C. Südhof. (AFP)
The Karolinska Institute in Stockholm announced the winners: James E. Rothman of Yale University; Randy W. Schekman of the University of California, Berkeley; and Dr Thomas C. Südhof of Stanford University.
The molecules are moved around the cell in small packages called vesicles, and each scientist discovered different facets that are needed to ensure that the right cargo is shipped to the correct destination at precisely the right time.
Their research solved the mystery of how cells organise their transport system, the Karolinska committee said. Dr Schekman discovered a set of genes that were required for vesicle traffic.
Dr Rothman unravelled protein machinery that allows vesicles to fuse with their targets to permit transfer of cargo. Dr Südhof revealed how signals instruct vesicles to release their cargo with precision.
The tiny vesicles, which have a covering known as membranes, shuttle the cargo between different compartments or fuse with the membrane. The transport system activates nerves. It also controls the release of hormones.
Disturbances in this exquisitely precise control system for transporting and delivering cellular cargo cause serious damage that, in turn, can contribute to conditions like neurological diseases, diabetes, and immunological disorders.
Dr Scheckman, 65, who was born in St Paul, Minnesota, used yeast cells as a model system when he began his research in the 1970s. He found that vesicles piled up in parts of the cell and that the cause was genetic. He went on to identify three classes of genes that control different facets of the cell’s transport system.
Dr Scheckman studied at the University of California in Los Angeles and at Stanford University, where he obtained his PhD in 1974.
In 1976, he joined the faculty of the University of California at Berkeley, where he is currently professor in the Department of Molecular and Cell biology. Dr Schekman is also an investigator of Howard Hughes Medical Institute.
Dr Rothman, 63, who was born in Haverhill, Massachusetts, studied vesicle transport in mammalian cells in the 1980s and 1990s. He discovered that a protein complex allows vesicles to dock and fuse with their target membranes. In the fusion process, proteins on the vesicles and target membranes bind to each other like the two sides of a zipper.
The fact that there are many such proteins and that they bind only in specific combinations ensures that cargo is delivered to a precise location.
The same principle operates inside the cell and when a vesicle binds to the cell’s outer membrane to release its contents. Dr Rothman received a PhD from Harvard Medical School in 1976, was a postdoctoral fellow at Massachusetts Institute of Technology, and moved in 1978 to Stanford University, where he started his research on the vesicles of the cell.