New grant may help SFU scientist Peter Unrau show that RNA is the key element
By Leah Bjornson
Photos by SFU News
Questions like “What is the purpose of life?” and “Where did we come from?” have captivated humankind for as long as our species has been alive. Now, supplemented with a key research grant, an SFU scientist may be on track to helping answer the questions of life’s origins.
Peter Unrau, a professor of molecular biology and biochemistry at SFU, is the recipient of one of this year’s Natural Sciences and Engineering Research Council (NSERC) Discovery Accelerator Supplement (DAS) awards. The award, valued at $120,000, is part of a $413 million national research funding announcement supporting thousands of researchers across the country who, according to NSERC, are investigating “high risk, novel or potentially transformative concepts and lines of inquiry.”
By investigating how life began on Earth about 3.7 billion years ago, Unrau is doing just that. His main work revolves around the hypothesis that RNA played a substantive role in the early evolution of life. This theory, developed by Sid Altman and Thomas Cech in the 1960s and coined in the 1980s, is known as the RNA World Hypothesis.
“DNA is where we store our genetic information,” explained Unrau. “And we convert that into RNA by transcription, and once we have that RNA it gets translated by the ribosome into proteins, which are the machines that keep us alive . . . The problem with the model is that it doesn’t explain where we came from. Proteins are very useful, but where did the first proteins come from?”
To solve this puzzle, the RNA World Hypothesis proposes that RNA molecules were the first complex molecules, existing even before DNA and protein. RNA stores genetic information like DNA, but can also catalyze complex chemical reactions just like an enzyme protein. Therefore, scientists propose that it may have been able to carry out the necessary functions for creating life.
Unrau explained, “There’s a lot of critical machines in the cell that are not actually protein based, for example, the ribosome. It’s responsible for protein synthesis and yet its made out of RNA, not protein. This suggests a way that evolution could have worked really early in evolution. You could have had this machine made out of RNA which was responsible for making proteins that one by one replaced the RNA catalysts of the RNA World. If this picture is true then you should be able to catalyze all of the reactions that are catalyzed by proteins today using only RNA.”
To support the hypothesis, Unrau and his team are trying to find evidence that “machines” that can do the kinds of reactions, that would have been important in such a world, can be built out of RNA.
“We’re trying ultimately to make a system that can evolve on its own, built out of RNA, and that would stand on its own,” said Unrau. “It would be a parallel example of a living system that would have no history connecting it directly to life we have today, and so from that point of view it would be a good example of what kind of things are really important in living systems and what kind of things are not important.”
Such research could potentially lead to answering larger questions of the existence of other life in the Universe. “Right now there’s a really open and exciting scientific question which is how common is life in the Universe, and its either really common or we’re really lucky to be here.”
