Ohsumi’s Nobel Is Big Win for Autophagy, Yeast & ASCB

Yoshinori Ohsumi. Photo by Tokyo Institute of Technology.

Yoshinori Ohsumi. Photo by Tokyo Institute of Technology.

The 2016 Nobel Prize in Physiology or Medicine to ASCB member Yoshinori Ohsumi of the Tokyo Institute of Technology is a big win for basic research into a fundamental mechanism of cellular life, the degradation of proteins through the process of autophagy. Ohsumi revolutionized the field in the early 1990s with his discovery of the genes (ATG) that control protein degradation in vacuoles in Saccharomyces cerevisiae. It is also a win for yeast genetics and for a long line of ASCB members who pioneered research into protein degradation and recycling.

 

Ohsumi, who heads the Cell Biology Research Unit at the Tokyo Institute of Technology, won the 2016 Nobel for his discovery of autophagy mechanisms. He will receive a roughly $936,000 prize for his work. Only 38 of the 106 Nobel Prize in Physiology or Medicine awards have been given to only one person. Typically the award is shared between two or three researchers.

 

Ohsumi’s discoveries came more than a half century after the discovery by biochemical studies of the lysosome in 1955 by Rockefeller researcher and ASCB member Christian de Duve. Electron microscopy studies confirmed their existence and led in 1974 to the Nobel in Medicine for de Duve and George Palade, one of the founders of the ASCB, along with Albert Claude. It was de Duve, in 1963, who coined the term “autophagy” as the cellular process of self-eating, which allows cells to recycle their contents rather than dispose of them.

 

Yet it wasn’t until the early 1990s that the genes and proteins involved in autophagy were identified by Ohsumi. Using the model yeast S. cerevisiae, Ohsumi discovered a method for identifying the ATP genes. He blocked vacuolar degradation using yeast mutants, then induced autogphagy by starving the cells. With the vacuole impaired, the autophagosomes accumulated in the cell allowing researchers to easily visualize these compartments, which are typically small, infrequent, and difficult to identify. This technique allowed for the discovery of autophagy genes and mechanisms.

 

Ohsumi earned his PhD from the University of Tokyo and was a postdoc at Rockefeller University from 1974-1977 with Gerald Edelman, ASCB member and 1972 Nobel Prize winner. Ohsumi returned to the University of Tokyo as a Research Associate in 1977, where he is now Emeritus Professor. Ohsumi joined the Tokyo Institute of Technology in 2009. Ohsumi won a 2015 Canada Gairdner Award—often considered a precursor to the Nobel Prize as 73 of its recipients have gone on to win Nobel Prizes since its inception in 1959. He gave a symposium talk at the ASCB Annual Meeting in 2014 titled “Molecular Dissection of Autophagy in Yeast.” He is a signer of the San Francisco Declaration on Research Assessment (DORA).

 

Ohsumi’s prize brings the total of Nobels in either Medicine or Chemistry won by ASCB members to 32.

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Christina Szalinski is a science writer with a PhD in Cell Biology from the University of Pittsburgh.