A trio of American scientists won the Nobel Prize for Medicine for pioneering work on the body's cell transport system, unlocking insights into diabetes, immune disorders and other diseases.

James Rothman, Randy Schekman and Thomas Suedhof shared the prize for discovering how molecules vital to cellular functioning are shunted around in an internal freight system, tucked inside sacs called vesicles.

They also helped resolve how the vesicles arrive on time and in the right place -- a major riddle, given that this takes place in a microscopic environment humming with movement.

If the package fails to show up at the right time, or goes to the wrong location, this can cause cellular malfunction.

"Through their discoveries, Rothman, Schekman and Suedhof have revealed the exquisitely precise control system for the transport and delivery of cellular cargo," the Nobel panel said.

"Without this wonderfully precise organisation, the cell would lapse into chaos."

Suedhof, a professor of molecular and cellular physiology at Stanford University in California, was driving a car "in the middle of Spain" when reached by the Nobel Committee several hours after the announcement.

"Are you serious? Oh, my God," he said when given the news, according to a recording carried on the official Nobel website.

Suedhof, who was born in 1955 in Germany but is now a US citizen, welcomed sharing the prize with two others, saying "one tends to overestimate oneself, but I think it's more than fair".

When asked about his capacity for work, he answered: "My wife thinks I am crazy. I don't know. I am incredibly driven."

Original post:

Cellular breakthrough earns trio Nobel for medicine