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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MDPI AG
2022-10-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/23/20/12178 |
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| author | Daniele Santorelli Francesca Troilo Francesca Fata Francesco Angelucci Nicola Demitri Giorgio Giardina Luca Federici Flavia Catalano Adele Di Matteo Carlo Travaglini-Allocatelli |
| author_facet | Daniele Santorelli Francesca Troilo Francesca Fata Francesco Angelucci Nicola Demitri Giorgio Giardina Luca Federici Flavia Catalano Adele Di Matteo Carlo Travaglini-Allocatelli |
| author_sort | Daniele Santorelli |
| collection | DOAJ |
| 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. |
| first_indexed | 2024-03-09T09:47:17Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-09T09:47:17Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-d5f05fc70aaa44dea9d9bee4fb0273082023-12-02T00:31:56ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672022-10-0123201217810.3390/ijms232012178Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological VariantDaniele Santorelli0Francesca Troilo1Francesca Fata2Francesco Angelucci3Nicola Demitri4Giorgio Giardina5Luca Federici6Flavia Catalano7Adele Di Matteo8Carlo Travaglini-Allocatelli9Department of Biochemical Sciences “A Rossi Fanelli”—Sapienza, University of Rome, 00185 Rome, ItalyInstitute of Molecular Biology and Pathology National Research Council of Italy, 00185 Rome, ItalyDepartment of Health, Life and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, ItalyDepartment of Health, Life and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, ItalyElettra—Sincrotrone Trieste, S.S. 14 Km 163.5, Area Science Park, Basovizza, 34149 Trieste, ItalyDepartment of Biochemical Sciences “A Rossi Fanelli”—Sapienza, University of Rome, 00185 Rome, ItalyDepartment of Innovative Technologies in Medicine and Dentistry and Center for Advanced Studies and Technology (CAST), University of Chieti “G. d’Annunzio”, 66100 Chieti, ItalyDepartment of Biochemical Sciences “A Rossi Fanelli”—Sapienza, University of Rome, 00185 Rome, ItalyInstitute of Molecular Biology and Pathology National Research Council of Italy, 00185 Rome, ItalyDepartment of Biochemical Sciences “A Rossi Fanelli”—Sapienza, University of Rome, 00185 Rome, ItalyThe 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.https://www.mdpi.com/1422-0067/23/20/12178FMRPKH domainsfolding mechanismfolding intermediateamyloid fibrils |
| spellingShingle | Daniele Santorelli Francesca Troilo Francesca Fata Francesco Angelucci Nicola Demitri Giorgio Giardina Luca Federici Flavia Catalano Adele Di Matteo Carlo Travaglini-Allocatelli Folding Mechanism and Aggregation Propensity of the KH0 Domain of FMRP and Its R138Q Pathological Variant International Journal of Molecular Sciences FMRP KH domains folding mechanism folding intermediate amyloid fibrils |
| 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 | FMRP KH domains folding mechanism folding intermediate amyloid fibrils |
| url | https://www.mdpi.com/1422-0067/23/20/12178 |
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