Japanese biologist Yoshinori Ohsumi on Monday won the Nobel Prize in Physiology and Medicine for the seminal work on the cell fundamental process called autophagy, which literally means “self-feeding.”
Autophagy, which was discovered in the 1950s, allows cells to recycle their content rather than simply dispose of proteins and other molecules that have already been used.
The mechanism helps cells destroy invading bacteria and viruses, remove damaged proteins, and respond to stress and starvation. Disruptions in autophagy have been linked to diseases like Parkinson’s, cancer and type 2 diabetes
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Ohsumi identified key genes that promote autophagy and showed that the process is controlled by a cascade of proteins. Its central experiments were made in the 1990s, making this another prize when the prize committee reached decades in honor. The prize money goes to 95 million Japanese yen, or about $ 936,000.
“Ohsumi discoveries led to a new paradigm in understanding how the cell recycles its content,” said the Nobel committee in your citation . “His discoveries opened the way to the understanding of the fundamental importance of autophagy in many physiological processes, and adaptation to starvation or response to infection [and] … conditions like cancer and neurological disease.”
A number of academic laboratories and biotechnology companies are working on the manipulation of autophagy for growth tumor block reduce damage to the heart myocardial ischemia, and suppress viral infections .
There is no doubt that autophagy is a key cellular process, worthy of a Nobel.
However, the committee’s decision to grant the award Ohsumi alone can cause some ripples in the scientific community.
When observers crystal ball in Thomson Reuters made their predictions Nobel in 2013 forecast that the medicine prize finally meet the discoveries of autophagy, called a trio of possible winners: Ohsumi, Tokyo Institute of Technology and Daniel J. Klionsky of the University of Michigan and Noboru Mizushima of the University of Tokyo.
work Ohsumi is based on the discovery in the 1950s that the vesicles within cells – called Autophagosomes – wrap worn structures such as mitochondria or even pieces of cytoplasm and move to what had been considered the garbage collection cell a structure called the lysosome. In 1988, he began studying Ohsumi autophagy in yeast, a unicellular organism that is a favorite of biologists because of their relatively simple genetics.
“nothing is known about why or how constituents cytoplasmic degraded in the vacuole,” as the lysosome it is called in yeast, Thomson Reuters she said in 2013. “When I started my own lab [in 1988] only for myself, I decided to work on this issue. … My hope was that the yeast vacuole could become a good system for studying the molecular mechanisms of intracellular protein degradation. “
found that autophagy seemed to occur when the yeast was running out of nutrients: Yeast cells their own pieces and recycling them to stay alive collapse, allowing them to survive a month or more with little support outside .
Ohsumi discovered that some of mutant yeast were terrible in autophagy and died a few days later. He identified the mutant genes, a family called ATG, in 1992; as he told Thomson Reuters, “The identification of these genes evoked a revolutionary change in the field of research of autophagy.”
When Mizushima joined his laboratory, he and Ohsumi together succeeded in identifying the mutant proteins and their interactions. Mizushima created mutant mice that were deficient in autophagy. That helped reveal the key role of autophagy plays in normal development: In very young embryos, for example, autophagy recycles maternal proteins in your account. And when cells are deprived of nutrition who cannibalize themselves in order to survive.
“I am proud that molecular studies of autophagy in mammals and plants also originated in my lab,” Ohsumi said in 2013. “Mizushima [and another colleague] so well developed excellent progress in mammals there autophagy. ”
Mice whose mutations that prevent autophagy, Mizushima and others also discovered, develop way more tumors than normal mice. In Parkinson’s disease, cells stop to clean and recycle defective mitochondria.
This process – autophagy of mitochondria – “. The leaders of this revolution autophagy” has been approach Klionsky something which in 2009 led scientists observers to call it one of
Under the terms of the will of Alfred Nobel, up to three awards may be appointed for each of the scientific awards. But the committee was with Ohsumi alone.
“I figured that if the Committee had to name just one, would Ohsumi,” said David Pendlebury of Thomson Reuters, which helps make predictions Nobel company. Ohsumi is “pioneering and high-level figure, even if Mizushima work extended significantly, as Klionsky to a lesser extent in the confirmation [their] findings.”
selections Thomson Reuters, added, “is supposed to recognize the important contributions of individuals, even if they are not selected at the end for the Nobel Prize, and this is a good example.”
This story has been updated with more information about the work of Ohsumi.