DNA carries the code for carrying out biological life, yet DNA is an unstable molecule. These two descriptions of DNA seem at odds with each other, especially when the prevailing view in media promotes that humans carry a stable genetic code throughout their lifetime. The reality is that DNA in all organisms is in a dynamic state with its environment, constantly becoming damaged and undergoing processes for damage reversal and repair. Sometimes, those processes are not exact, and sometimes to combat infection, DNA is purposefully altered. These processes result in mutations. Mutations readily appear in microorganisms as an adaptive advantage, enabling bacteria, viruses, or fungi to become resistant to pharmaceuticals or immune responses. These organisms have proteins that purposefully induce DNA mutations in times of stress. While humans share similar proteins, a surprising discovery over 20 years ago showed that humans have additional proteins in our cells that specialize in mutating DNA. The benefit of these specialized promutagenic proteins is still being understood, as are the risks. While these proteins have multiple benefits in immunity, they also pose a risk that presents as cancer.

Dr. Linda Chelico (PhD) is a professor in the Department of Biochemistry, Microbiology, and Immunology. Her research spans biochemistry, virology, and cancer biology. She earned her PhD in 2004 from the University of Saskatchewan (USask), specializing in the study of DNA repair in fungi. It was then that Chelico became amazed at the potential of mutations in DNA for an organism’s adaptability. Chelico then completed postdoctoral training at the University of Southern California with Myron F. Goodman, who studies multiple mutationinducing polymerases in bacteria. While she thought she would work on that topic, instead she worked on a new protein family that was discovered shortly before her arrival. Chelico brought this expertise to USask in 2009. The protein family her lab studies purposefully induces mutations as part of the immune response in humans. Chelico was the first to purify and characterize multiple proteins from this newly discovered family. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at https://www.ted.com/tedx