Aaron Ciechanover is a biochemist who, in 2004, shared the Nobel Prize in Chemistry with fellow Israeli Avram
Hershko and Irwin Rose of the US ‘for the discovery of ubiquitin-mediated protein degradation’. Scientists already knew how most proteins are produced, but what prevented cells from being overloaded by stockpiled proteins? In the early 1980’s Ciechanover, Hershko and Rose discovered how redundant proteins were broken down by a regulated system.
Ciechanover was born in Haifa in 1947, in what was then the British Protectorate of Palestine (it became Israel the following year), his Polish parents having moved there in the 1920’s with their families. Aaron and his elder brother Joseph were encouraged to study from an early age, and it was Joseph who bought Aaron his first microscope at the age of 11. Ciechanover majored in biology at school, and went on to receive his MSc in 1970 and his MD in 1975 from the Hadassah Medical School of the Hebrew University in Jerusalem. After three years military service as a combat physician in the Israel Defense Forces, he joined in 1976 the laboratory of Hershko in the Faculty of Medicine at the Technion (Israel Institute of Technology), in Haifa, where he received his DSc in 1981.
With two fellowships (from the Leukemia Society of America and the Israel Cancer Research Fund), Ciechanover went on to carry out postgraduate studies under the supervision of Harvey Lodish at MIT. Three years later, in 1984, he returned to Israel to join the Faculy of medicine at the Technion where he continued his research with many students, fellows and physicians, and where he is currently a Distinguished Research Professor in the Center for Cancer and Vascular Biology in the Rappaport Faculty of Medicine and Research Institute. In 2000 he received the Albert Lasker Award for Basic Medical Research and in 2003 the Israel Prize for Biological Research. Among many esteemed bodies he is a member of the Israeli Academy of Sciences and Humanities, the Pontifical Academy of Sciences of the Vatican and the USA national Academy of Sciences (Foreign Associate). He has been married to Menucha, a physician (geriatrician) and a graduate of Tel Aviv University School of Medicine, since 1975. They have one son, Yitzhak – Isaac.
Sadly, his parents did not live to see his success – Aaron’s mother died in 1958, and his father in 1964.
In the late 1970s and early 80s, Ciechanover, Hershko, and Rose worked together and discovered that cells destroy redundant proteins in a phased process. A molecule called ubiquitin (“as it was thought to be ubiquitous – everywhere”) attaches to a target protein and accompanies it to a proteasome – a complex of enzymes that break the protein into shorter peptides that are then further degraded into amino acids, the basic components of which proteins consist. Only proteins carrying a ubiquitin molecule are admitted, and the ubiquitin detaches itself to be reused. Their work enabled later to explain how the cell controls processes such as cell division, DNA repair, the mode of action of the immune system, and the way the cell maintains the quality of its proteins. Diseases such as certain malignancies and neurodegenerative disorders, as well as inflammatory diseases can result when protein degradation does not work properly, and knowledge of the process has led already to the development of a powerful anti-cancer drug, and others are in the pipeline.
This text and the picture of the Nobel Laureate were taken from the book: "NOBELS. Nobel Laureates photographed by Peter Badge" (WILEY-VCH, 2008).
Picture: © Peter Badge/ Foundation Lindau Nobelprizewinners Meetings at Lake Constance |