2rsk
RNA aptamer against prion protein in complex with the partial binding peptide
Structural highlights
DiseasePRIO_BOVIN Note=Variations in PRNP are responsible of transmissible bovine spongiform encephalopathies (BSE), a class of neurodegenerative diseases that affect various mammals. These diseases are caused by abnormally folded prion proteins. BSE can be subdivided into at least three groups: classical, H-type and L-type, with the latter 2 collectively referred to as atypical BSE. Susceptibility or resistance to a BSE disease can be influenced by at least 3 factors related to the host prion protein: protein expression levels, number of octapeptide repeats, and specific polymorphisms. In cattle, as in humans, BSEs can occur as infectious, spontaneous and genetic diseases. FunctionPRIO_BOVIN May play a role in neuronal development and synaptic plasticity. May be required for neuronal myelin sheath maintenance. May play a role in iron uptake and iron homeostasis. Soluble oligomers are toxic to cultured neuroblastoma cells and induce apoptosis (in vitro). Association with GPC1 (via its heparan sulfate chains) targets PRNP to lipid rafts. Also provides Cu(2+) or ZN(2+) for the ascorbate-mediated GPC1 deaminase degradation of its heparan sulfate side chains (By similarity). Publication Abstract from PubMedPrion proteins (PrPs) cause prion diseases, such as bovine spongiform encephalopathy. The conversion of a normal cellular form (PrP(C)) of PrP into an abnormal form (PrP(Sc)) is thought to be associated with the pathogenesis. An RNA aptamer that tightly binds to and stabilizes PrP(C) is expected to block this conversion and to thereby prevent prion diseases. Here, we show that an RNA aptamer comprising only 12 residues, r(GGAGGAGGAGGA) (R12), reduces the PrP(Sc) level in mouse neuronal cells persistently infected with the transmissible spongiform encephalopathy agent. Nuclear magnetic resonance analysis revealed that R12, folded into a unique quadruplex structure, forms a dimer and that each monomer simultaneously binds to two portions of the N-terminal half of PrP(C), resulting in tight binding. Electrostatic and stacking interactions contribute to the affinity of each portion. Our results demonstrate the therapeutic potential of an RNA aptamer as to prion diseases. Anti-prion activity of an RNA aptamer and its structural basis.,Mashima T, Nishikawa F, Kamatari YO, Fujiwara H, Saimura M, Nagata T, Kodaki T, Nishikawa S, Kuwata K, Katahira M Nucleic Acids Res. 2013 Jan 1;41(2):1355-1362. Epub 2012 Nov 24. PMID:23180780[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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