The Effect of Octapeptide Repeats on Prion Folding and Misfolding

Misfolding of prion protein (PrP) into amyloid aggregates is the central feature of prion diseases. PrP has an amyloidogenic C-terminal domain with three α-helices and a flexible tail in the N-terminal domain in which multiple octapeptide repeats are present in most mammals. The role of the octapept...

Full description

Bibliographic Details
Main Authors: Kun-Hua Yu, Mei-Yu Huang, Yi-Ru Lee, Yu-Kie Lin, Hau-Ren Chen, Cheng-I Lee
Format: Article
Language:English
Published: MDPI AG 2021-02-01
Series:International Journal of Molecular Sciences
Subjects:
Online Access:https://www.mdpi.com/1422-0067/22/4/1800
_version_ 1797396836184489984
author Kun-Hua Yu
Mei-Yu Huang
Yi-Ru Lee
Yu-Kie Lin
Hau-Ren Chen
Cheng-I Lee
author_facet Kun-Hua Yu
Mei-Yu Huang
Yi-Ru Lee
Yu-Kie Lin
Hau-Ren Chen
Cheng-I Lee
author_sort Kun-Hua Yu
collection DOAJ
description Misfolding of prion protein (PrP) into amyloid aggregates is the central feature of prion diseases. PrP has an amyloidogenic C-terminal domain with three α-helices and a flexible tail in the N-terminal domain in which multiple octapeptide repeats are present in most mammals. The role of the octapeptides in prion diseases has previously been underestimated because the octapeptides are not located in the amyloidogenic domain. Correlation between the number of octapeptide repeats and age of onset suggests the critical role of octapeptide repeats in prion diseases. In this study, we have investigated four PrP variants without any octapeptides and with 1, 5 and 8 octapeptide repeats. From the comparison of the protein structure and the thermal stability of these proteins, as well as the characterization of amyloids converted from these PrP variants, we found that octapeptide repeats affect both folding and misfolding of PrP creating amyloid fibrils with distinct structures. Deletion of octapeptides forms fewer twisted fibrils and weakens the cytotoxicity. Insertion of octapeptides enhances the formation of typical silk-like fibrils but it does not increase the cytotoxicity. There might be some threshold effect and increasing the number of peptides beyond a certain limit has no further effect on the cell viability, though the reasons are unclear at this stage. Overall, the results of this study elucidate the molecular mechanism of octapeptides at the onset of prion diseases.
first_indexed 2024-03-09T00:57:23Z
format Article
id doaj.art-2cbc1eef76dd44fd81c7322a836054aa
institution Directory Open Access Journal
issn 1661-6596
1422-0067
language English
last_indexed 2024-03-09T00:57:23Z
publishDate 2021-02-01
publisher MDPI AG
record_format Article
series International Journal of Molecular Sciences
spelling doaj.art-2cbc1eef76dd44fd81c7322a836054aa2023-12-11T16:46:14ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672021-02-01224180010.3390/ijms22041800The Effect of Octapeptide Repeats on Prion Folding and MisfoldingKun-Hua Yu0Mei-Yu Huang1Yi-Ru Lee2Yu-Kie Lin3Hau-Ren Chen4Cheng-I Lee5Department of Biomedical Sciences, National Chung Cheng University, 168 University Road, Min-Hsiung Chia-Yi 62102, TaiwanDepartment of Biomedical Sciences, National Chung Cheng University, 168 University Road, Min-Hsiung Chia-Yi 62102, TaiwanDepartment of Biomedical Sciences, National Chung Cheng University, 168 University Road, Min-Hsiung Chia-Yi 62102, TaiwanDepartment of Biomedical Sciences, National Chung Cheng University, 168 University Road, Min-Hsiung Chia-Yi 62102, TaiwanDepartment of Biomedical Sciences, National Chung Cheng University, 168 University Road, Min-Hsiung Chia-Yi 62102, TaiwanDepartment of Biomedical Sciences, National Chung Cheng University, 168 University Road, Min-Hsiung Chia-Yi 62102, TaiwanMisfolding of prion protein (PrP) into amyloid aggregates is the central feature of prion diseases. PrP has an amyloidogenic C-terminal domain with three α-helices and a flexible tail in the N-terminal domain in which multiple octapeptide repeats are present in most mammals. The role of the octapeptides in prion diseases has previously been underestimated because the octapeptides are not located in the amyloidogenic domain. Correlation between the number of octapeptide repeats and age of onset suggests the critical role of octapeptide repeats in prion diseases. In this study, we have investigated four PrP variants without any octapeptides and with 1, 5 and 8 octapeptide repeats. From the comparison of the protein structure and the thermal stability of these proteins, as well as the characterization of amyloids converted from these PrP variants, we found that octapeptide repeats affect both folding and misfolding of PrP creating amyloid fibrils with distinct structures. Deletion of octapeptides forms fewer twisted fibrils and weakens the cytotoxicity. Insertion of octapeptides enhances the formation of typical silk-like fibrils but it does not increase the cytotoxicity. There might be some threshold effect and increasing the number of peptides beyond a certain limit has no further effect on the cell viability, though the reasons are unclear at this stage. Overall, the results of this study elucidate the molecular mechanism of octapeptides at the onset of prion diseases.https://www.mdpi.com/1422-0067/22/4/1800prionoctapeptidefoldingmisfoldingfibril
spellingShingle Kun-Hua Yu
Mei-Yu Huang
Yi-Ru Lee
Yu-Kie Lin
Hau-Ren Chen
Cheng-I Lee
The Effect of Octapeptide Repeats on Prion Folding and Misfolding
International Journal of Molecular Sciences
prion
octapeptide
folding
misfolding
fibril
title The Effect of Octapeptide Repeats on Prion Folding and Misfolding
title_full The Effect of Octapeptide Repeats on Prion Folding and Misfolding
title_fullStr The Effect of Octapeptide Repeats on Prion Folding and Misfolding
title_full_unstemmed The Effect of Octapeptide Repeats on Prion Folding and Misfolding
title_short The Effect of Octapeptide Repeats on Prion Folding and Misfolding
title_sort effect of octapeptide repeats on prion folding and misfolding
topic prion
octapeptide
folding
misfolding
fibril
url https://www.mdpi.com/1422-0067/22/4/1800
work_keys_str_mv AT kunhuayu theeffectofoctapeptiderepeatsonprionfoldingandmisfolding
AT meiyuhuang theeffectofoctapeptiderepeatsonprionfoldingandmisfolding
AT yirulee theeffectofoctapeptiderepeatsonprionfoldingandmisfolding
AT yukielin theeffectofoctapeptiderepeatsonprionfoldingandmisfolding
AT haurenchen theeffectofoctapeptiderepeatsonprionfoldingandmisfolding
AT chengilee theeffectofoctapeptiderepeatsonprionfoldingandmisfolding
AT kunhuayu effectofoctapeptiderepeatsonprionfoldingandmisfolding
AT meiyuhuang effectofoctapeptiderepeatsonprionfoldingandmisfolding
AT yirulee effectofoctapeptiderepeatsonprionfoldingandmisfolding
AT yukielin effectofoctapeptiderepeatsonprionfoldingandmisfolding
AT haurenchen effectofoctapeptiderepeatsonprionfoldingandmisfolding
AT chengilee effectofoctapeptiderepeatsonprionfoldingandmisfolding