Editing Prion (section)

=== Normal function of PrP ===
The physiological function of the prion protein remains poorly understood. While data from in vitro experiments suggest many dissimilar roles, studies on PrP [[knockout mouse|knockout mice]] have provided only limited information because these animals exhibit only minor abnormalities. In research done in mice, it was found that the cleavage of PrP in peripheral nerves causes the activation of [[myelin]] repair in [[Schwann cells]] and that the lack of PrP proteins caused demyelination in those cells.<ref>{{cite journal | title = Healthy prions protect nerves | journal = Nature | vauthors = Abbott A | s2cid = 84980140 | doi = 10.1038/news.2010.29 | date=2010-01-24 }}</ref>

==== PrP and regulated cell death ====
MAVS, RIP1, and RIP3 are prion-like proteins found in other parts of the body. They also polymerise into filamentous amyloid fibers which initiate regulated cell death in the case of a viral infection to prevent the spread of [[Virus#Etymology|virions]] to other, surrounding cells.<ref>{{cite journal | vauthors = Nailwal H, Chan FK | title = Necroptosis in anti-viral inflammation | journal = Cell Death and Differentiation | volume = 26 | issue = 1 | pages = 4–13 | date = January 2019 | pmid = 30050058 | pmc = 6294789 | doi = 10.1038/s41418-018-0172-x }}</ref>

==== PrP and long-term memory ====
A review of evidence in 2005 suggested that PrP may have a normal function in the maintenance of [[long-term memory]].<ref>{{cite journal | vauthors = Shorter J, Lindquist S | title = Prions as adaptive conduits of memory and inheritance | journal = Nature Reviews. Genetics | volume = 6 | issue = 6 | pages = 435–450 | date = June 2005 | pmid = 15931169 | doi = 10.1038/nrg1616 | s2cid = 5575951 }}</ref> As well, a 2004 study found that mice lacking genes for normal cellular PrP protein show altered [[hippocampus|hippocampal]] [[long-term potentiation]].<ref>{{cite journal | vauthors = Maglio LE, Perez MF, Martins VR, Brentani RR, Ramirez OA | title = Hippocampal synaptic plasticity in mice devoid of cellular prion protein | journal = Brain Research. Molecular Brain Research | volume = 131 | issue = 1–2 | pages = 58–64 | date = November 2004 | pmid = 15530652 | doi = 10.1016/j.molbrainres.2004.08.004 }}</ref><ref>{{cite journal | vauthors = Caiati MD, Safiulina VF, Fattorini G, Sivakumaran S, Legname G, Cherubini E | title = PrPC controls via protein kinase A the direction of synaptic plasticity in the immature hippocampus | journal = The Journal of Neuroscience | volume = 33 | issue = 7 | pages = 2973–83 | date = February 2013 | pmid = 23407955 | pmc = 6619229 | doi = 10.1523/JNEUROSCI.4149-12.2013 }}</ref> A recent study that also suggests why this might be the case, found that neuronal protein [[CPEB]] has a similar genetic sequence to yeast prion proteins. The prion-like formation of CPEB is essential for maintaining long-term synaptic changes associated with long-term memory formation.<ref>{{cite journal | vauthors = Sudhakaran IP, Ramaswami M | title = Long-term memory consolidation: The role of RNA-binding proteins with prion-like domains | journal = RNA Biology | volume = 14 | issue = 5 | pages = 568–586 | date = May 2017 | pmid = 27726526 | pmc = 5449092 | doi = 10.1080/15476286.2016.1244588 }}</ref>

==== PrP and stem cell renewal ====
A 2006 article from the Whitehead Institute for Biomedical Research indicates that PrP expression on stem cells is necessary for an organism's self-renewal of [[bone marrow]]. The study showed that all long-term [[hematopoietic stem cell]]s express PrP on their cell membrane and that hematopoietic tissues with PrP-null stem cells exhibit increased sensitivity to cell depletion.<ref>{{cite journal | vauthors = Zhang CC, Steele AD, Lindquist S, Lodish HF | title = Prion protein is expressed on long-term repopulating hematopoietic stem cells and is important for their self-renewal | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 103 | issue = 7 | pages = 2184–9 | date = February 2006 | pmid = 16467153 | pmc = 1413720 | doi = 10.1073/pnas.0510577103 | doi-access = free | bibcode = 2006PNAS..103.2184Z }}</ref>

==== PrP and innate immunity ====
There is some evidence that PrP may play a role in [[innate immunity]], as the expression of [[PRNP]], the PrP gene, is upregulated in many viral infections and PrP has antiviral properties against many viruses, including [[HIV]].<ref>{{cite journal | vauthors = Lathe R, Darlix JL | title = Prion Protein PRNP: A New Player in Innate Immunity? The Aβ Connection | journal = Journal of Alzheimer's Disease Reports | volume = 1 | issue = 1 | pages = 263–275 | date = December 2017 | pmid = 30480243 | pmc = 6159716 | doi = 10.3233/ADR-170037 }}</ref>