The same protein that, in an altered shape, causes mad cow disease and other neurodegenerative disorders maintains the body's cache of blood-producing stem cells, a new study suggests.
Called the prion protein, or PrP, it's scattered throughout the body in mammals. When, in rare occurrences, PrP becomes misshapen, it causes neurodegenerative diseases in cows (SN: 1/10/04, p. 19: Cow Madness: Disease's U.S. emergence highlights role of feed ban), deer (SN: 1/28/06, p. 52: Available to subscribers at Hunter Beware: Infectious proteins found in deer muscle), people (SN: 10/4/97, p. 212: http://www.sciencenews.org/pages/sn_arc97/10_4_97/fob1.htm), and other species. However, researchers haven't been sure what function the normal protein performs.
"For years, we've wondered why evolution has preserved this protein, what positive role it could possibly be playing," says Susan Lindquist of the Whitehead Institute for Biomedica