Israelis Aaron Ciechanover and Avram Hershko and American Irwin Rose won the 2004 Nobel Prize in chemistry (search) Wednesday for discovering a key way cells destroy unwanted proteins -- starting with a chemical "kiss of death."

When the process goes wrong, several hundred diseases can result, including cervical cancer and cystic fibrosis. So the work provides the basis for developing new therapies.

The Royal Swedish Academy of Sciences (search) honored Ciechanover, 57, Hershko, 67, and Rose, 78, for work they did in the 1980s.

Proteins are the busy bees of cells, carrying out many jobs, but few researchers had been interested in how cells destroy them when they're no longer needed, the academy said. The three scientists uncovered a process that starts when the doomed protein is grabbed by a particular molecule, marking it for destruction. The marked proteins are then chopped to pieces.

The process governs such key processes as cell division, DNA repair and quality control of newly produced proteins, as well as important parts of the body's immune defenses against disease, the academy said in its citation.

Ciechanover is director of the Rappaport Family Institute for Research in Medical Sciences at the Technion, in Haifa, Israel, while Hershko, originally from Hungary, is a professor there.

Rose is a specialist at the department of physiology and biophysics at the college of medicine at the University of California, Irvine.

Ciechanover told reporters, "I'm happy that I can speak on the phone at all and that I remember I my English. "I'm not myself, that's for sure, not for a while."

It's the first time an Israeli has won a Nobel science prize, although Israelis have won peace and literature Nobels. "I am as proud for myself as I am for my country," Ciechanover said.

This year's award announcements began Monday with the Nobel Prize in medicine going to Americans Richard Axel and Linda B. Buck.

Axel and Buck were selected by a committee at Stockholm's Karolinska Institutet for their work on the sense of smell. They clarified the intricate biological pathway from the nose to the brain that lets people sense smells.

On Tuesday, Americans David J. Gross, H. David Politzer and Frank Wilczek won the physics prize for their explanation of the force that binds particles inside the atomic nucleus.

Their work has helped science get closer to "a theory for everything," the academy said in awarding the prize.

The winner of the literature prize will be announced Thursday. The Bank of Sweden Prize in Economic Sciences in Memory of Alfred Nobel will be announced Oct. 11.

The winner of the coveted peace prize -- the only one not awarded in Sweden -- will be announced Friday in Oslo, Norway.

The prizes, which include a $1.3 million check, a gold medal and a diploma, are presented on Dec. 10, the anniversary of Nobel's death in 1896.