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Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological Variant
The K-homology (KH) domains are small, structurally conserved domains found in proteins of different origins characterized by a central conserved βααβ “core” and a GxxG motif in the loop between the two helices of the KH core. In the eukaryotic KHI type, additional αβ elements decorate the “core” at...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9603430/ https://www.ncbi.nlm.nih.gov/pubmed/36293035 http://dx.doi.org/10.3390/ijms232012178 |
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author | Santorelli, Daniele Troilo, Francesca Fata, Francesca Angelucci, Francesco Demitri, Nicola Giardina, Giorgio Federici, Luca Catalano, Flavia Di Matteo, Adele Travaglini-Allocatelli, Carlo |
author_facet | Santorelli, Daniele Troilo, Francesca Fata, Francesca Angelucci, Francesco Demitri, Nicola Giardina, Giorgio Federici, Luca Catalano, Flavia Di Matteo, Adele Travaglini-Allocatelli, Carlo |
author_sort | Santorelli, Daniele |
collection | PubMed |
description | The K-homology (KH) domains are small, structurally conserved domains found in proteins of different origins characterized by a central conserved βααβ “core” and a GxxG motif in the loop between the two helices of the KH core. In the eukaryotic KHI type, additional αβ elements decorate the “core” at the C-terminus. Proteins containing KH domains perform different functions and several diseases have been associated with mutations in these domains, including those in the fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein crucial for the control of RNA metabolism whose lack or mutations lead to fragile X syndrome (FXS). Among missense mutations, the R138Q substitution is in the KH0 degenerated domain lacking the classical GxxG motif. By combining equilibrium and kinetic experiments, we present a characterization of the folding mechanism of the KH0 domain from the FMRP wild-type and of the R138Q variant showing that in both cases the folding mechanism implies the accumulation of an on-pathway transient intermediate. Moreover, by exploiting a battery of biophysical techniques, we show that the KH0 domain has the propensity to form amyloid-like aggregates in mild conditions in vitro and that the R138Q mutation leads to a general destabilization of the protein and to an increased fibrillogenesis propensity. |
format | Online Article Text |
id | pubmed-9603430 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-96034302022-10-27 Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological Variant Santorelli, Daniele Troilo, Francesca Fata, Francesca Angelucci, Francesco Demitri, Nicola Giardina, Giorgio Federici, Luca Catalano, Flavia Di Matteo, Adele Travaglini-Allocatelli, Carlo Int J Mol Sci Article The K-homology (KH) domains are small, structurally conserved domains found in proteins of different origins characterized by a central conserved βααβ “core” and a GxxG motif in the loop between the two helices of the KH core. In the eukaryotic KHI type, additional αβ elements decorate the “core” at the C-terminus. Proteins containing KH domains perform different functions and several diseases have been associated with mutations in these domains, including those in the fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein crucial for the control of RNA metabolism whose lack or mutations lead to fragile X syndrome (FXS). Among missense mutations, the R138Q substitution is in the KH0 degenerated domain lacking the classical GxxG motif. By combining equilibrium and kinetic experiments, we present a characterization of the folding mechanism of the KH0 domain from the FMRP wild-type and of the R138Q variant showing that in both cases the folding mechanism implies the accumulation of an on-pathway transient intermediate. Moreover, by exploiting a battery of biophysical techniques, we show that the KH0 domain has the propensity to form amyloid-like aggregates in mild conditions in vitro and that the R138Q mutation leads to a general destabilization of the protein and to an increased fibrillogenesis propensity. MDPI 2022-10-12 /pmc/articles/PMC9603430/ /pubmed/36293035 http://dx.doi.org/10.3390/ijms232012178 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Santorelli, Daniele Troilo, Francesca Fata, Francesca Angelucci, Francesco Demitri, Nicola Giardina, Giorgio Federici, Luca Catalano, Flavia Di Matteo, Adele Travaglini-Allocatelli, Carlo Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological Variant |
title | Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological Variant |
title_full | Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological Variant |
title_fullStr | Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological Variant |
title_full_unstemmed | Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological Variant |
title_short | Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological Variant |
title_sort | folding mechanism and aggregation propensity of the kh0 domain of fmrp and its r138q pathological variant |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9603430/ https://www.ncbi.nlm.nih.gov/pubmed/36293035 http://dx.doi.org/10.3390/ijms232012178 |
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