Limited understanding of the functional diversity of N-linked glycans as a major gap of prion biology

IV Baskakov - Prion, 2017 - Taylor & Francis
Prion, 2017Taylor & Francis
Among a broad range of hypotheses on the molecular nature of transmissible spongiform
encephalopathy or scrapie agents discussed in 1960s was a hypothesis of self-replicating
polysaccharides. While the studies of the past 40 years provided unambiguous proof that
this is not the case, emerging evidence suggests that carbohydrates in the form of sialylated
N-linked glycans, which are a constitutive part of mammalian prions or PrPSc, are essential
in determining prion fate in an organism. The current extra-view article discusses recent …
Abstract
Among a broad range of hypotheses on the molecular nature of transmissible spongiform encephalopathy or scrapie agents discussed in 1960s was a hypothesis of self-replicating polysaccharides. While the studies of the past 40 years provided unambiguous proof that this is not the case, emerging evidence suggests that carbohydrates in the form of sialylated N-linked glycans, which are a constitutive part of mammalian prions or PrPSc, are essential in determining prion fate in an organism. The current extra-view article discusses recent advancements on the role of N-linked glycans and specifically their sialylation status in controlling prion fate. In addition, this manuscript introduces a new concept on the important role of strain-specific functional carbohydrate epitopes on the PrPSc surface as main determinants of strain-specific biologic features. According to this concept, individual strain-specific folding patterns of PrPSc govern selection of PrPC sialoglycoforms expressed by a host that can be accommodated within particular PrPSc structures. Strain-specific patterns of functional carbohydrate epitopes formed by N-linked glycans on PrPSc surfaces define strain-specific biologic features. As a constitutive part of PrPSc, the individual strain-specific patterns of carbohydrate epitopes propagate faithfully within a given host as long as individual strain-specific PrPSc structures are maintained, ensuring inheritance of strain-specific biologic features.
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