The process of autophagy (literally \u201cself-eating\u201d\u009d) is so vital to our survival that it was the focus of the 2016 Nobel Prize in Physiology or Medicine announced in October. Winner Yoshinori Ohsumi described the discovery of this complex process as a surprise. He watched as cells wrapped entire proteins and organelles in a protective membrane\u201d\u201dand then shredded them to pieces with enzymes. It was the equivalent of watching a wrecking ball take down a skyscraper, reducing a majestic work of architecture into a pile of bricks.<\/p>\n
The destruction seemed counterintuitive, even dangerous. The mantra of cellular biology up to that point had been that building proteins\u201d\u201dnot destroying them\u201d\u201dwas the key to health and survival. The controlled but nonetheless devastating demolition of these structures into which so much energy and resources had been poured was perplexing. Wouldn\u2019t this starving cell prefer to have all of its organelles\u201d\u201djust as a body would prefer to have all of its organs? Why, in the face of adversity, would a cell demolish something it had worked very hard to build?<\/p>\n
As Ohsumi\u2019s team investigated further, the metaphor used for three decades changed: Autophagy isn\u2019t cellular self-cannibalism so much as it is cellular pruning. \u201cOrganisms never waste precious resources without good reason,\u201d\u009d Ohsumi said, \u201cand degradation is a process essential for the creation of new life.\u201d\u009d At its core this process was one of destruction, but it was not reckless. A cell that was indiscriminately destroying pieces of itself was not going to last long, but one that could select old, broken, misshapen, or malignant proteins and recycle them into something new would flourish.<\/p>\n