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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...

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Autores principales: Santorelli, Daniele, Troilo, Francesca, Fata, Francesca, Angelucci, Francesco, Demitri, Nicola, Giardina, Giorgio, Federici, Luca, Catalano, Flavia, Di Matteo, Adele, Travaglini-Allocatelli, Carlo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
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.
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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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