The Swedish academy praised Dr Blobel for discovering how proteins are transported within the human cell, work that could help to unlock the secrets of diseases such as cystic fibrosis.

Dr Guenter Blobel likens the signalling system to a postal service

The Nobel Prize Committee said the discovery "has had an immense impact on modern cell biological research".

In a statement, the committee said: "Dr Blobel's research has helped explain the molecular mechanism behind several genetic diseases.

The Daily Telegraph's Science Correspondent Roger Highfield puts the work in context

"A number of human hereditary diseases are caused by errors in these signals and transport mechanisms

"Dr Blobel's research has also contributed to the development of a more effective use of cells as 'protein factories' for the production of important drugs."

Dr Blobel's work has made it possible to identify the signals which direct proteins to different parts of a cell, just as address tags on suitcases ensure luggage arrives at the right airport.

Important implications

The Nobel Assembly said Dr Blobel's work had several important implications.

"One example is the hereditary disease primary hyperoxaluria, which causes kidney stones at an early age.

Dr Gunter Blobel's work has major implications

"In some forms of familial hypercholesterolemia, a very high level of cholesterol in the blood is due to deficient transport signals.

"Other hereditary diseases, e.g., cystic fibrosis, are caused by the fact that proteins do not reach their proper destination."

Dr Blobel, a cellular and molecular biologist, discovered in the early 1970s that newly synthesized proteins have an intrinsic signal that is essential for directing them.

His work in the following 20 years concentrated on uncovering the detail underlying these processes.

Dr Blobel was born in pre-war Germany in the Silesian town of Waltersdorf, but is now an American citizen.