A 71-year-old old Japanese biologist has won the 2016 Nobel Prize in physiology or medicine for his pioneering work studying the processes used by cells to consume damaged proteins and organelles and recycle their contents to provide nutrients to other cellular structures.
According to the Associated Press and Los Angeles Times, Yoshinori Ohsumi, a biologist at the Tokyo Institute of Technology, began his research into the field known as autophagy back in the late 1980s, and over the course of his career, he identified 15 genes that oversee the process.
In experiments conducted during the 1990s and first published in the Journal of Cell Biology, Ohsumi used baker’s yeast to identify those genes, then went on to discovered the underlying mechanisms for autophagy in the yeast. Those mechanisms, he learned, were similar to the ones used by human cells to relocate and break down worn-out cellular contents.
“Ohsumi’s discoveries led to a new paradigm in our understanding of how the cell recycles its content,” the Nobel Assembly at Karolinska Institutet explained Monday in a statement. “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,” they added. Ohsumi is the 107th recipient of the Nobel Prize in physiology or medicine since 1905, and he will also take home a prize of 8 million kronor ($930,000) for his efforts, according to the AP.
Processes discovered by Ohsumi linked to cancer, Alzheimer’s disease
While autophagy (which literally means “self-eating” in Greek) has been known for more than five decades, it wasn’t until Ohsumi’s research that its “fundamental importance” to the field of medicine was fully recognized, the Nobel Assembly explained as part of their statement.
The autophagy process provides the cell with nutrients and building blocks for renewal. (Credit: Nobel Prize)
His “brilliant” work resulted in the identification of the first genes required for the process, they noted, and he ultimately revealed that the processes are “controlled by a cascade of proteins and protein complexes, each regulating a distinct stage of autophagosome initiation and formation.” Disturbances in the autophagy processes, the Times reported, have been linked to cancer, Type-2 diabetes, Parkinson’s disease, Alzheimer’s disease and other age-related conditions.
In 1988, Ohsumi opened his own lab and began studying protein degradation in the vacuole, an organelle similar to the lysosome in our cells. Specifically, he cultured mutated yeast cells which lacked vacuolar degradation enzymes and starved them to stimulate autophagy so that they would accumulate autophagosomes, with the ultimate goal of monitoring them using a microscope.
The vaculoes were filled with small, non-degraded vesicles within a matter of hours, proving that autophagy existed in yeast cells while also finding a way to identify the genes involved, the prize committee explained. After publishing this breakthrough in 1992, Ohsumi then used his modified yeast in experiments that induced autophagy, allowing him to identify the first genes essential for the process and to characterize the proteins encoded by those genes. Thanks to his efforts, as well as the work of those following him, scientists now know that similar processes are at work in our cells as well, and they now have the tools to investigate those mechanisms.
Ohsumi told the AP that he never thought he would win a Nobel Prize for his research, calling it “a dream” of his as a child. “I don’t feel comfortable competing with many people, and instead I find it more enjoyable doing something nobody else is doing,” the biologist explained. “In a way, that’s what science is all about, and the joy of finding something inspires me.”
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Image credit: Jiji Press
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