Dataset Information

Residues surrounding the glycosylphosphatidylinositol anchor attachment site of PrP modulate prion infection: insight from the resistance of rabbits to prion disease.

ABSTRACT: Prion diseases are a group of transmissible, invariably fatal neurodegenerative diseases that affect both humans and animals. According to the protein-only hypothesis, the infectious agent is a prion (proteinaceous infectious particle) that is composed primarily of PrP(Sc), the disease-associated isoform of the cellular prion protein, PrP. PrP(Sc) arises from the conformational change of the normal, glycosylphosphatidylinositol (GPI)-anchored protein, PrP(C). The mechanism by which this process occurs, however, remains enigmatic. Rabbits are one of a small number of mammalian species reported to be resistant to prion infection. Sequence analysis of rabbit PrP revealed that its C-terminal amino acids differ from those of PrP from other mammals and may affect the anchoring of rabbit PrP through its GPI anchor. Using a cell culture model, this study investigated the effect of the rabbit PrP-specific C-terminal amino acids on the addition of the GPI anchor to PrP(C), PrP(C) localization, and PrP(Sc) formation. The incorporation of rabbit-specific C-terminal PrP residues into mouse PrP did not affect the addition of a GPI anchor or the localization of PrP. However, these residues did inhibit PrP(Sc) formation, suggesting that these rabbit-specific residues interfere with a C-terminal PrP(Sc) interaction site.

SUBMITTER: Nisbet RM

PROVIDER: S-EPMC2903296 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Residues surrounding the glycosylphosphatidylinositol anchor attachment site of PrP modulate prion infection: insight from the resistance of rabbits to prion disease.

Nisbet Rebecca M RM Harrison Christopher F CF Lawson Victoria A VA Masters Colin L CL Cappai Roberto R Hill Andrew F AF

Journal of virology 20100428 13

Prion diseases are a group of transmissible, invariably fatal neurodegenerative diseases that affect both humans and animals. According to the protein-only hypothesis, the infectious agent is a prion (proteinaceous infectious particle) that is composed primarily of PrP(Sc), the disease-associated isoform of the cellular prion protein, PrP. PrP(Sc) arises from the conformational change of the normal, glycosylphosphatidylinositol (GPI)-anchored protein, PrP(C). The mechanism by which this process ...[more]

PMID: 20427543

Similar Datasets

Project description:hGHDAF28 is a chimaeric protein consisting of human growth hormone fused to a crippled signal sequence for glycosylphosphatidylinositol (GPI)-anchor addition from decay-accelerating factor, and serves as a model for quality control of GPI-anchor addition. hGHDAF28 is retained in a pre-Golgi compartment and degraded intracellularly by a mechanism with similarity to that for other endoplasmic reticulum (ER)-retained proteins (Field, Moran, Lee, Keller and Caras (1994) J. Biol. Chem. 269, 10830-10837). We have studied the specific pathway of degradation for hGHDAF28 using a number of compounds which affect protein folding and trafficking pathways in eukaryotic cells. We found that high concentrations of dithiothreitol (DTT) accelerated loss of hGHDAF28 by degradation from cell lysates, without promoting secretion or alteration of disulphide-bond distribution, in contrast to a number of other examples of ER-retained proteins where DTT alters disulphide-bond formation. Additionally, degradation of hGHDAF28 was sensitive to pH, being promoted at pH 6.0 and inhibited at pH 8.0; however, the latter effect was transient, indicating incomplete blockade. Degradation was also partially enhanced by depletion of ER calcium with thapsigargin, but this was again a partial and transient effect. Furthermore, degradation was temperature sensitive, with a gradual decrease in rate observed at lower temperatures. However, a sharp decrease in turnover between 15 degrees C and 20 degrees C, indicative of a requirement for transport to a post-ER compartment, was not observed. Degradation of hGHDAF28 was insensitive to treatment with nocodozole or compounds preventing cytoplasmic autophagy, suggesting that ER degradation is independent of classical autophagy and microtubule-dependent processes. In addition, disruption of N-glycosylation with tunicamycin, or inhibition of processing of immature N-glycan chains with castanospermine or deoxynojirimycin, had little effect on the stability of hGHDAF28, suggesting that disruption of the BiP/calnexin quality-control system by bulk cellular secretory proteins does not influence the ER-degradation pathway of hGHDAF28. Intermolecular hGHDAF28 cysteine bonds result in the formation of aggregates which are probably important in the retention of the molecule. The insensitivity of this structure to reduction in vivo, together with the enhanced degradation rate, indicates that DTT mediates its effect on stability via a molecule involved in degradation of hGHDAF28, possibly a thiol-sensitive protease.

Dataset Information

Residues surrounding the glycosylphosphatidylinositol anchor attachment site of PrP modulate prion infection: insight from the resistance of rabbits to prion disease.

Publications

Residues surrounding the glycosylphosphatidylinositol anchor attachment site of PrP modulate prion infection: insight from the resistance of rabbits to prion disease.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets