Critical significance of the region between Helix 1 and 2 for efficient dominant-negative inhibition by conversion-incompetent prion protein
| العنوان: | Critical significance of the region between Helix 1 and 2 for efficient dominant-negative inhibition by conversion-incompetent prion protein |
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| المؤلفون: | Yuzuru Taguchi, Hermann M. Schätzl, Tetsuyuki Kitamoto, Arla M. A. Mistica |
| المصدر: | PLoS Pathogens, Vol 9, Iss 6, p e1003466 (2013) PLoS Pathogens |
| بيانات النشر: | Public Library of Science (PLoS), 2013. |
| سنة النشر: | 2013 |
| مصطلحات موضوعية: | Conformational change, Protein Folding, PrPSc Proteins, animal diseases, Dominant negative, Glycobiology, Oligosaccharides, Biochemistry, Protein Structure, Secondary, Prion Diseases, Mice, lcsh:QH301-705.5, Protein Metabolism, 0303 health sciences, Zoonotic Diseases, Protein Stability, 030302 biochemistry & molecular biology, Recombinant Proteins, Cell biology, Protein Transport, Infectious Diseases, Veterinary Diseases, Medicine, Intracellular, Research Article, Gene isoform, lcsh:Immunologic diseases. Allergy, Glycan, Protein Structure, Proteasome Endopeptidase Complex, Immunology, Biophysics, Biology, Microbiology, 03 medical and health sciences, Virology, Cell Line, Tumor, Genetics, Animals, Humans, PrPC Proteins, Prion protein, Protein Interactions, Molecular Biology, 030304 developmental biology, Glycoproteins, Veterinary Prion Diseases, Autophagy, Proteins, Protein Structure, Tertiary, nervous system diseases, Metabolism, Solubility, lcsh:Biology (General), Helix, Proteolysis, biology.protein, Parasitology, Veterinary Science, lcsh:RC581-607 |
| الوصف: | Prion diseases are fatal infectious neurodegenerative disorders in man and animals associated with the accumulation of the pathogenic isoform PrPSc of the host-encoded prion protein (PrPc). A profound conformational change of PrPc underlies formation of PrPSc and prion propagation involves conversion of PrPc substrate by direct interaction with PrPSc template. Identifying the interfaces and modalities of inter-molecular interactions of PrPs will highly advance our understanding of prion propagation in particular and of prion-like mechanisms in general. To identify the region critical for inter-molecular interactions of PrP, we exploited here dominant-negative inhibition (DNI) effects of conversion-incompetent, internally-deleted PrP (ΔPrP) on co-expressed conversion-competent PrP. We created a series of ΔPrPs with different lengths of deletions in the region between first and second α-helix (H1∼H2) which was recently postulated to be of importance in prion species barrier and PrP fibril formation. As previously reported, ΔPrPs uniformly exhibited aberrant properties including detergent insolubility, limited protease digestion resistance, high-mannose type N-linked glycans, and intracellular localization. Although formerly controversial, we demonstrate here that ΔPrPs have a GPI anchor attached. Surprisingly, despite very similar biochemical and cell-biological properties, DNI efficiencies of ΔPrPs varied significantly, dependant on location and inversely correlated with the size of deletion. This data demonstrates that H1∼H2 and the region C-terminal to it are critically important for efficient DNI. It also suggests that this region is involved in PrP-PrP interaction and conversion of PrPC into PrPSc. To reconcile the paradox of how an intracellular PrP can exert DNI, we demonstrate that ΔPrPs are subject to both proteasomal and lysosomal/autophagic degradation pathways. Using autophagy pathways ΔPrPs obtain access to the locale of prion conversion and PrPSc recycling and can exert DNI there. This shows that the intracellular trafficking of PrPs is more complex than previously anticipated. Author Summary Prion diseases are deadly infectious diseases of the brain characterized by accumulation of a pathologic protein (PrPSc) which is derived from the normal prion protein (PrPc). Prions replicate by direct contact in a template-directed refolding process which involves conversion of PrPC into PrPSc. Identifying the modalities of this interaction can advance our molecular understanding of prion diseases. Like substrates and competitive inhibitors of enzymes, a conversion-incompetent PrP can inhibit conversion of normal PrPC, a phenomenon known as dominant-negative inhibition (DNI). Interestingly, some conversion-incompetent PrPs efficiently cause DNI but others do not, presumably depending on affinity for PrPSc and integrity of interaction interface. We utilized DNI to characterize the PrP-PrP interaction interface in cultured cells. We created a series of PrPs with internal deletions in the region between helix 1 and 2 and evaluated their DNI. We found an inverse correlation between deletion size and DNI which suggests that this region plays an important role in PrP-PrP interaction. We also found that such PrPs are subject to various cellular degradation pathways and that a fraction of them reaches the intracellular locale of prion conversion. Further investigation of such prion proteins might help elucidating the cellular mechanisms of the PrPC-PrPSc interaction. |
| اللغة: | English |
| تدمد: | 1553-7374 1553-7366 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::067320df182c847ffcc89a0f3bd37b3bTest http://europepmc.org/articles/PMC3694865?pdf=renderTest |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....067320df182c847ffcc89a0f3bd37b3b |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15537374 15537366 |
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