Amino acid sequence of the Pekingese dog prion protein gene.

:  Prion diseases are neurodegenerative disorders in humans and various animals associated with a proteinaceous infectious pathogen, designated prion. Canine species seem to be resistant to the infection and no natural prion disease has been documented in dogs. The polymorphisms within the open reading frame of the prion protein gene are associated with the susceptibility of the species, and species barriers, to prion diseases. In the present study, the open reading frame of the prion protein (Prnp) gene from 16 Pekingese dogs was cloned and screened for polymorphisms. One nucleotide polymorphism (G489C) was found; the G to C nucleotide substitution results in a glutamic to aspartic acid change at codon 163. The amino acid sequence of the Pekingese Prnp gene showed the highest homology with that of greyhounds (AF042843), when compared with other Prnp genes in GenBank. Glu/Asp163 and asparagine 107 in canine prion protein genes were replaced by asparagine and serine, respectively, in all the prion protein genes examined. These substitutes might in turn affect the potential intermolecular interactions critical for cross-species transmission of prion disease and might influence the canine susceptibility to prion infection.