Read with caution!
This post was written during early stages of trying to understand a complex scientific problem, and we didn't get everything right. The original author no longer endorses the content of this post. It is being left online for historical reasons, but read at your own risk.
Aguzzi et al’s 2008 review article, The Prion’s Elusive Reason for Being reviews what all we know (or knew in 2008) about the question many of us are wondering: what is PrP for? The question behind the question (for some of us at least): can we just suppress it or do we need it to live?
Regrettably, it seems the answer so far is:
Despite the progress discussed above, several important issues in the prion ﬁeld remain unresolved. Most conspicuously, both the physiological function of PrPC and the molecular pathways leading to the fatal neurodegeneration in prion diseases remain unknown.
But this (rather lengthy) article nevertheless seems to contain a huge amount of useful information that we can dissect and discuss here once we have time to give the whole thing a thorough read.