Transmissible spongiform function

The prion protein PrP represents a central player in transmissible spongiform encephalopathies (TSEs), also known as prion diseases (for review see Lasmezas and Weiss, 2000)). The physiological role of the cellular isoform of PrP termed PrP is speculative so far (for review see (Weissmann, 1996)) and might involve control of circadian activity rhythms and sleep (Tobler et ai, 1996), maintenance of cerebellar Purkinje cell (Sakaguchi et al, 1996), and normal synaptic functions (Collinge et al., 1994 Fournier et al., 1995 Kitamoto et al., 1992). Because several reports do not describe any phenotype for PrP (Bueler et al, 1992 Lledo et al, 1996 Manson et al., 1994), the only proved role of prpc is its necessity for the development of TSEs (Bueler et al., 1993)... 

If the protein fails to fold properly, its shape is incorrect and it cannot perform its intended function. Aberrations in protein folding appear to contribute to human diseases. Among these are Alzheimer s disease, prion diseases, emphysema and cirrhosis, amyelotrophic lateral sclerosis (Lou Gehrig s disease), cystic fibrosis, some tumors, and osteogenesis imperfecta (King et al., 2002). The prion that seems to cause ovine transmissible spongiform encephalopathy, for instance, appears as a pleated sheet rather than a smooth helix. 

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