Yoshinori Ohsumi, a professor at Tokyo Institute of Technology, has won this year's Nobel Prize in Medicine or Physiology for his research elucidating autophagy.
"Ohsumi's discoveries led to a new paradigm in our understanding of how the cell recycles its content," the Nobel committee says in a press release. "His discoveries opened the path to understanding the fundamental importance of autophagy in many physiological processes, such as in the adaptation to starvation or response to infection. Mutations in autophagy genes can cause disease, and the autophagic process is involved in several conditions including cancer and neurological disease."
Ohsumi earned his PhD in 1974 from the University of Tokyo, but the New York Times notes that his thesis was "unimpressive" and he had trouble finding a job. He then pursued a postdoc at Rockefeller University where he was to study in vitro fertilization in mice, but switched to yeast. He used yeast as his model organism for his series of experiments on autophagy in the 1990s.
Prior to Ohsumi's work, scientists knew that there was structure inside cells that degraded proteins and other cellular parts. "What he showed was that it wasn't a waste dump. It was a recycling plant. This was a really sophisticated machinery that recycled damaged or long-lived proteins," Juleen Zierath, the chair of the medicine Nobel committee, tells NPR.
"All I can say is, it's such an honor," Ohsumi tells reporters at the Tokyo Institute of Technology, according to NHK, a Japanese broadcaster. "I'd like to tell young people that not all can be successful in science, but it's important to rise to the challenge."