This traffic control system keeps activities inside cells from descending into chaos and has helped researchers gain a better understanding of a range of diseases including diabetes and disorders affecting the immune system, the committee said.
The discoveries have helped doctors diagnose a severe form of epilepsy and immune deficiency diseases in children, Nobel committee secretary Goran Hansson said. In the future, scientists hope the research could lead to medicines against more common types of epilepsy, diabetes and other metabolism deficiencies, he said.
Rothman, 62, is a professor at Yale University while Schekman, 64, is at the University of California, Berkeley. Suedhof, 57, joined Stanford University in 2008. Schekman said he was awakened at 1 a.m. at his home in California by the chairman of the prize committee and was still suffering from jetlag after returning from a trip to Germany the night before.
"I wasn't thinking too straight. I didn't have anything elegant to say," he told The Associated Press. "All I could say was 'Oh my God,' and that was that."
He called the prize a wonderful acknowledgment of the work he and his students had done and said he knew it would change his life.
"I called my lab manager and I told him to go buy a couple bottles of Champagne and expect to have a celebration with my lab," he said.
The Nobel committee said the three researchers work on "vesicle traffic" -- the transport system of our cells -- helped scientists understand how "cargo is delivered to the right place at the right time" inside cells. Vesicles are tiny bubbles that act as cargo carriers.
"Imagine hundreds of thousands of people who are traveling around hundreds of miles of streets; how are they going to find the right way? Where will the bus stop and open its doors so that people can get out?" said Hansson, the committee's secretary. "There are similar problems in the cell, to find the right way between the different organelles and out to the surface of the cell."
In the 1970s, Schekman discovered a set of genes that were required for vesicle transport, while Rothman revealed in the 1980s and 1990s how proteins dock with their target membranes like two sides of a zipper. Also in the '90s, Suedhof found out how vesicles release their cargo with precision.
"This is not an overnight thing. Most of it has been accomplished and developed over many years, if not decades," Rothman told the AP.
Asked if the Nobel might change his work or funding, he said, "I honestly don't know. It's a new experience."
Rothman said he lost grant money for the work recognized by the Nobel committee, but he will now reapply, hoping the Nobel prize will make a difference in receiving funding.
The medicine prize kicked off this year's Nobel announcements. The awards in physics, chemistry, literature, peace and economics will be announced by other prize juries this week and next. Each prize is worth 8 million Swedish kronor ($1.2 million).
"These discoveries have had a major impact on our understanding of how cargo is delivered with timing and precision within and outside the cell," the committee said.
Rothman and Schekman won the Albert Lasker Basic Medical Research Award for their research in 2002 -- an award often seen as a precursor of a Nobel Prize.
Established by Swedish industrialist Alfred Nobel, the Nobel Prizes have been handed out by award committees in Stockholm and Oslo since 1901. The winners always receive their awards on Dec. 10, the anniversary of Nobel's death in 1896.
Last year's medicine award went to Britain's John Gurdon and Japan's Shinya Yamanaka for their contributions to stem cell science.
Associated Press writers Matt Surman in London and Stephen Singer in Hartford, Conn., contributed to this report.
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