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Biography

Aaron Ciechanover was born in Haifa, Israel, in October 1947 to Polish parents who had to move there in the 1920s with their families. He was encouraged to study from an early age and he majored in biology at school. He studied medicine at the Hebrew University Medical School in Jerusalem, receiving an MSc in 1970 and his MD in 1974.

In 1976 he joined Avram Hershko’s laboratory in the Faculty of Medicine at Teknion (Israel Institute of Technology) where he received a Ph.D. in 1981. He then went on to become a postdoctoral fellow in the Department of Biology at MIT (Massachusetts Institute of Technology) where he studied asialoglycoprotein and transferrin receptors in the laboratory of Harvey Lodish. Three years later he returned to Israel where he continued his research.

Today, Ciechanover is a professor in the Biochemistry Unit and the director of the Rappaport Family Institute for Research in Medical Sciences at the Technion (Israel Institute of Technology) in Haifa. He became a full professor at the Technion in 1992, after working as an associate professor there from 1987 to 1992.

His decision to study medicine stemmed from his belief that it was a profession with a future. He wanted to conduct basic research and, at a time when scientists were discovering how the molecules of life were built, along with Abraham Hersko, he decided to attempt to discover how proteins were destroyed. The characterisation of protein degradation led him to receive the Nobel Prize, and has resulted in the explanation of the pathologies of some neurodegenerative diseases such as Parkinson’s, Alzheimer’s and some cancers.

The life and work of Aaron Ciechanover are deeply rooted in and influenced by Judaism and Israel. It is for this reason that, with only a brief intermission, his scientific career has unfolded in Israel, where he is – through his presence and work – able to contribute to and shape the presence and future of the State of Israel.

His research

All living things are made up of proteins: plants, animals and, therefore, us – humans. In the past few decades biochemistry has come a long way towards explaining how the cell produces all its various proteins. But as to the breaking down of proteins, this has not sparked the interest of many researchers. Aaron Ciechanover, Avram Hershko and Irwin Rose went against the grain and at the beginning of the 1980s discovered one of the cell’s most important cyclical processes, regulated protein degradation. For this, they were rewarded with the Nobel Prize in Chemistry in 2004.

Aaron Ciechanover, Avram Hershko and Irwin Rose have brought us to realise that the cell functions as a highly-efficient checking station where proteins are built up and broken down at a furious rate. The degradation is not indiscriminate but takes place through a process that is controlled in detail so that the proteins to be broken down at any given moment are given a molecular label, a ‘kiss of death’, to be dramatic. The labelled proteins are then fed into the cells’ “waste disposers”, the so called proteasomes, where they are chopped into small pieces and destroyed.

The label consists of a molecule called ubiquitin. This fastens to the protein to be destroyed, accompanies it to the proteasome where it is recognised as the key in a lock, and signals that a protein is on the way for disassembly. Shortly before the protein is squeezed into the proteasome, its ubiquitin label is disconnected for re-use.

Thanks to the work of the three Laureates it is now possible to understand at molecular level how the cell controls a number of central processes by breaking down certain proteins and not others. Examples of processes governed by ubiquitin-mediated protein degradation are cell division, DNA repair, quality control of newly-produced proteins, and important parts of the immune defence. When the degradation does not work correctly, we fall ill. Cervical cancer and cystic fibrosis are two examples. Knowledge of ubiquitin-mediated protein degradation offers an opportunity to develop drugs against these diseases and others.

(Modified abstract from “The Royal Swedish Academy of Sciences”)