Global analysis of protein degradation rates during prion infection

ABSTRACT: Prion diseases are rare, neurological disorders caused by the misfolding of the cellular prion protein (PrPC). The misfolded conformers aggregate into cytotoxic fibrils (PrPSc) that facilitate the conversion of additional prion proteins into their misfolded form. Intracellular PrPSc aggregates primarily accumulate within late endosomes and lysosomes, organelles that participate in the degradation and turnover of a large subset of the proteome. Thus, intracellular accumulation of PrPSc aggregates have the potential to globally influence protein degradation kinetics. We have analyzed the proteome-wide effect of prion infection on protein degradation rates in N2a neuroblastoma cells by dynamic stable isotopic labeling with amino acids in cell culture (dSILAC) and bottom-up proteomics to quantify the degradation rates of more than 4700 proteins in prion-infected and uninfected cells. As expected, the degradation rate of the prion protein is significantly decreased upon aggregation in infected cells. The data indicate that dilution due to cell division, rather than degradation, is the dominant factor in clearance of PrPSc in infected N2a cells. Conversely, the degradation kinetics of the remainder of the N2a proteome generally increases upon infection. This effect occurs concurrently with increases in the cellular activities of autophagy and lysosomal hydrolases. The resulting enhancement in proteome flux may play a role in the survival of N2a cells during prion infection.

INSTRUMENT(S): Orbitrap Fusion Lumos, Q Exactive

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Cell Culture

DISEASE(S): Prion Disease

SUBMITTER: Charles Hutti  

LAB HEAD: Sina Ghaemmaghami

PROVIDER: PXD014577 | Pride | 2021-09-08

REPOSITORIES: Pride