If the cells that make up your body are little factories, then the shipping department just picked up a Nobel Prize this morning with the award for physiology or medicine going to researchers Randy Schekman of the University of California at Berkeley, James Rothman of Yale University, and Thomas Südhof of Stanford. These scientists don't work together, but their research does overlap and play off each other in important ways. In fact, this isn't the first time some of these men have shared major research awards.
What makes their work so important? It's really all about increasing our understanding of how individual cells operate and participate in major bodily systems like immunity or hormone control. If you built little models of cells back in grade school, you probably have a mental image of them as a sort of lumpy sack with a couple of things inside — a big fat nucleus and some squirrelly little mitochondria, mostly. But it turns out that there's a lot more happening in the interior of a cell than that. Much of that activity is centered around vesicles — bubbles in the fluid that fills a cell. There are many different kinds of vesicles doing many different jobs, but one of the important things they do is move molecules, either within the cell or from the cell to the outside world.
Here's how the Nobel website explains it:
In a large and busy port, systems are required to ensure that the correct cargo is shipped to the correct destination at the right time. The cell, with its different compartments called organelles, faces a similar problem: cells produce molecules such as hormones, neurotransmitters, cytokines and enzymes that have to be delivered to other places inside the cell, or exported out of the cell, at exactly the right moment. Timing and location are everything. Miniature bubble-like vesicles, surrounded by membranes, shuttle the cargo between organelles or fuse with the outer membrane of the cell and release their cargo to the outside. This is of major importance, as it triggers nerve activation in the case of transmitter substances, or controls metabolism in the case of hormones. How do these vesicles know where and when to deliver their cargo?
The "how" question is really what Schekman, Rothman, and Südhof's work is all about. By examining what happened in cells where this shipping system wasn't working properly, they were able to figure out how different parts of the system were actually supposed to be operating and were able to learn more about the genetic and environmental factors that can throw the cellular shipping department off its game. What they've learned is having a big impact on how researchers think about immune system disorders, diabetes (insulin is one of the chemicals that vesicles move around), and neurological problems linked to hormone transport.
Change your mental image of the interior of a cell with this illustration from a 1996 Scientific American story on Rothman's work. It'll give you a better feel for the vesicle action that's happening all over the place, all the time.
The Scientific American Podcast has a recording from the official announcement early this morning, which gets into some of the nitty-gritty detail on what vesicles do and what Schekman, Rothman, and Südhof contributed to our understanding of them.
Nature News has links to research papers written by the winners, and to more-easily-readable essays the three men wrote about the work.
Reuters has a nice summary of the research, too.
Image: Public Domain image of lipid vesicles, courtesy Wikipedia.