One mutant prion, Q24R, hinders the ability of misfolded proteins to aggregate into harmful clumps. It's like a dryer sheet that cuts down on static cling and makes it easier to fold laundry. Another helpful mutant prion known as G58D, assists the cell by speeding up its ability to unfold and refold misfolded proteins. That's more like a friend who helps untangle strings of holiday lights when they come out of storage.
DiSalvo's experiments showed how the mutants and cells work together. Cells would only be cured when she both added a mutant and allowed the cells' own quality assurance system to work. Adding the mutant G58D, for example, could cure a cell of infection by the Sup35 prion, but if she perturbed the cell's quality assurance system then G58D would not work.
The results show the importance of delving deeply into molecular networks, said Stefan Maas, who oversees Serio's and other cellular signaling grants at the National Institutes of Health.
"These results are a great example of the power of system-level studies," Maas said. "By showing how two beneficial mutants cure the cell of prions, this study has revealed that small changes applied to distinct components of a molecular network can dramatically alter the outcome for the cell. These new insights may lead to new strategies for preventing or treating disorders that involve protein deposits."
But those strategies may require turning proteins into pills. Serio noted that while beneficial mutant prions confer resistance
|Contact: David Orenstein|