It’s Nobel Prize season!
Beyond being a great way to recognize scientists and their achievements, the Nobel Prizes are an opportunity for everyone to learn about important discoveries and the scientific process. As a molecular biologist, I am always excited to see scientists in my field recognized for the prize in the category of Physiology and Medicine (there is no specific “Biology” category). This year’s prize is even more exciting to me personally because Yoshinori Ohsumi is being recognized for his work on autophagy, which he did by studying my favorite model organism, yeast!
Ohsumi studied how cells can break themselves down and recycle their component parts. This process is called autophagy, which literally means “self eating”. Cells can digest their various compartments and machinery before ultimately killing themselves entirely. While this may sound a little brutal, this process is very important for removing old, diseased, or damaged cells that might cause harm. This is especially important in multicellular organisms such as ourselves, but studying human cells can be very difficult. That was even more true in the late 80’s and 90’s when Ohsumi was doing these studies.
Enter in budding yeast! Yep, the same yeast that do all the hard work in brewing and baking are also on the job in biology labs around the world. Yeast are small, single-celled organisms that are easy to grow in the lab. And basic biological processes which govern how cells function are extremely similar in all organisms, so things we learn by studying yeast tell us a lot about how our own cells function.
One of the key studies that Ohsumi and his group are being recognized for is a genetic screen that identified some of the key players in the process of autophagy. To do this they treated yeast cells with a chemical that induces DNA mutations and looked for cells that had defects in the process of autophagy. A great thing about yeast is that they can be easily crossed, which is important for identifying the mutated genes. We can’t go around mating humans, and animals take months to mate, while yeast can mate and form offspring in just a few days. In doing so, Ohsumi’s group and others discovered systems in the cell that target proteins and membranes and signal the autophagy process.
While research around autophagy and the diseases that can occur in humans when it goes awry is still ongoing, the foundational insights into this process lend some thanks to the little and mighty yeast!