A campus professor and her research team have recently made a new discovery regarding the potentially revolutionary CRISPR protein system often found in bacteria.
CRISPR is a “genome-editing tool,” according to postdoctoral fellow David Taylor, who worked on the research. It cuts out a sequence of DNA from an offending organism, such as a virus, and inserts it into the bacterium, similar to a “cut and paste” function on computer.
Jennifer Doudna, campus professor of molecular and cell biology and chemistry, runs the research laboratory that discovered the structural mechanism by which the tool is able to capture genetic information from foreign bodies.
“CRISPR can best be understood as a pair of scissors,” Taylor said. “It’s cutting DNA. My part in the research shows how the scissors open to get to the DNA and cut it (out).”
There are multiple proteins contained within the CRISPR system, according to graduate student researcher and co-author of the paper James Nunez, including two called Cas1 and Cas2. These proteins act as “guards,” protecting the bacteria by policing the cell for foreign DNA and, if found, taking sections of that DNA and inserting it into the CRISPR locus — a site that helps the bacterium remember the virus.
The CRISPR locus, therefore, essentially holds “mug shots” of viruses that have previously infected the organism, according to Nunez.
The function of CRISPR is to assist in an organism’s adaptive immunity. By taking a segment of DNA from an attacker and introducing it to the organism, it allows the organism to build up a defense against that attacker.
CRISPR has enormous potential as a possible medicinal or therapeutic cure, according to postdoctoral fellow and Doudna Lab researcher Fuoguo Jiang. It presents the possibility of intentionally editing genes to be immune to certain diseases, or to “re-edit” cancerous genes in order to make them benign.
“There’s a lot of important work to still be done there,” Jiang said.
According to Taylor, investigating CRISPR has helped transform biological research.
Cas9 is another protein found in the CRISPR structure that cuts DNA, whereas Cas1 and Cas2 insert the cut DNA into a genome. Previously, researchers would have to go through an arduous process to be able to edit genes, but Cas9 can be used as a shortcut. Scientists can now easily edit and manipulate genes to discover the exact functions of what a genome does.
Some applications of CRISPR have already been discovered. Scientists at Kunming Biomedical International in China have successfully created “designer monkeys” with specific genetic mutations that were edited into their DNA by the CRISPR genome-editing tool.
“This (discovery) allows us to expand the available tools to edit genes in a wide variety of cells, including those from humans,” Nunez said in an email.
Contact Anderson Lanham at [email protected].