Molecular Cloning of a Human Prion Protein cDNA

Abstract

Creutzfeldt-Jakob disease (CJD) of humans and scrapie of animals are degenerative, transmissible neurologic diseases caused by prions. The only known macromolecules within prions are prion proteins (PrP). The cDNA encoding the hamster prion protein (PrP 27-30) has been cloned and sequenced (Oesch et al., 1985). Using that hamster PrP cDNA, we screened a human retina cDNA library and sequenced the cDNA clone with the longest hybridizing insert. This insert was found to contain a long open reading frame (ORF) encoding the human prion protein. Northern transfer analysis showed that a related poly(A)+RNA measuring approximately 2.5 kb is expressed in a variety of human neuroectodermal cell lines. Human PrP differed from hamster PrP at 27 of 253 amino acids and at 98 of 759 ORF nucleotides. Conservation of PrP amino acid sequence between hamster and human is nearly 90%, reflecting similar structural features and shared antigenicity of the two proteins (Bockman et al., 1985). The human PrP sequence contained a presumptive amino-terminal signal peptide of 22 amino acids, two hydrophobic segments of sufficient length to span membranes, and two possible sites for N-glycosylation. The conservation between the hamster and human prion proteins suggests that they may have an important role in cellular metabolism and may explain the similarities between scrapie and CJD.

Prion and doppel proteins bind to granule cells of the cerebellum

“…An alternative possibility is that PrP Sc is formed in the molecular layer where both PrP C and a ligand for MoPrP(Q218K)-Fc are found; once formed, PrP Sc is readily transported to the white matter where it is deposited. In support of this hypothesis are earlier in situ hybridization studies indicating that PrP mRNA expression is confined to neurons, in which PrP C is synthesized (51), and more recent investigations showing that PrP Sc formed in brain grafts implanted in Prnp 0/0 mice travels along white matter tracts throughout the brain (52). In this scenario, the search for ligands that bind to MoPrP(Q218K)-Fc might yield protein X and thus, the screening of cDNA expression libraries with MoPrP(Q218K)-Fc seems prudent.…”

Genotype-phenotype analysis in inherited prion disease with eight octapeptide repeat insertional mutation

“…R1 encodes a nonapeptide while R2-R4 encode octapetides. 6,26 Additional OPRI in the reported 8-OPRI families display two silent nucleotide substitutions designated as R2a and R3g. The insertion sites of additional OPRI are the same only for the M-E and Che families, their order differ in the Swedish and A family ( Table 11).…”

Molecular characterization of proteolytic cleavage sites of the Pseudomonas syringae effector AvrRpt2

“…In other brain regions, PrP gene expression occurred at an earlier age. In situ hybridization studies show that the highest levels of PrP mRNA are found in neurons (207).…”