News FocusNEURODEGENERATION

Acting Like a Prion Isn't Always Bad

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Science  04 Dec 2009:
Vol. 326, Issue 5958, pp. 1338
DOI: 10.1126/science.326.5958.1338

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Summary

In mad cow disease and related disorders, misfolded proteins called prions cause normal proteins to misfold and clump together, spreading havoc through the nervous system. Virtually any protein can misbehave like this when the conditions are right, and some researchers now suspect that prionlike mechanisms of protein misfolding and propagation may underlie a wide range of neurodegenerative disorders (see main text). But if this type of behavior in proteins is so dangerous, why hasn't evolution selected against it? One possibility is that it hasn't had to: Many of these diseases strike late in life, after the reproductive years are over. It's also possible that this type of protein folding isn't always bad.