Binding of neural cell adhesion molecules (N-CAMs) to the cellular prion protein

摘要: Abstract To identify molecular interaction partners of the cellular prion protein (PrPC), we sought to apply an in situ crosslinking method that maintains microenvironment PrPC. Mild formaldehyde mouse neuroblastoma cells (N2a) are susceptible infection revealed presence PrPC high mass (HMM) complexes 200 225 kDa. LC/MS/MS analysis identified three murine splice-variants neural cell adhesion molecule (N-CAM) complexes, which isolate with caveolae-like domains (CLDs). Enzymatic removal N-linked sugar moieties did not disrupt arguing PrP N-CAM occurs through amino acid side-chains. Additionally, similar levels PrP/N-CAM were found N2a and prion-infected (ScN2a) cells. With use N-CAM-specific peptide library, PrP-binding site was determined comprise β-strands C C′ within two consecutive fibronectin type III (FNIII) modules proximity membrane-attachment N-CAM. As by deletion mutants, face binding is formed N terminus, helix A (residues 144–154) adjacent loop region PrP. N-CAM-deficient (N-CAM−/−) mice intracerebrally challenged scrapie prions succumbed disease a mean incubation period 122 (±4.1, SEM) days, involved PrPSc replication. Our findings raise possibility may join carrying out some as yet unidentified physiologic function.