Conformational Plasticity of Centrin 1 from <i>Toxoplasma gondii</i> in Binding to the Centrosomal Protein SFI1
Centrins are calcium (Ca<sup>2+</sup>)-binding proteins that are involved in many cellular functions including centrosome regulation. A known cellular target of centrins is SFI1, a large centrosomal protein containing multiple repeats that represent centrin-binding motifs. Recently, a pr...
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MDPI AG
2022-08-01
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| Series: | Biomolecules |
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| Online Access: | https://www.mdpi.com/2218-273X/12/8/1115 |
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| author | Luca Bombardi Filippo Favretto Marco Pedretti Carolina Conter Paola Dominici Alessandra Astegno |
| author_facet | Luca Bombardi Filippo Favretto Marco Pedretti Carolina Conter Paola Dominici Alessandra Astegno |
| author_sort | Luca Bombardi |
| collection | DOAJ |
| description | Centrins are calcium (Ca<sup>2+</sup>)-binding proteins that are involved in many cellular functions including centrosome regulation. A known cellular target of centrins is SFI1, a large centrosomal protein containing multiple repeats that represent centrin-binding motifs. Recently, a protein homologous to yeast and mammalian SFI1, denominated TgSFI1, which shares SFI1-repeat organization, was shown to colocalize at centrosomes with centrin 1 from <i>Toxoplasma gondii</i> (TgCEN1). However, the molecular details of the interaction between TgCEN1 and TgSFI1 remain largely unknown. Herein, combining different biophysical methods, including isothermal titration calorimetry, nuclear magnetic resonance, circular dichroism, and fluorescence spectroscopy, we determined the binding properties of TgCEN1 and its individual N- and C-terminal domains to synthetic peptides derived from distinct repeats of TgSFI1. Overall, our data indicate that the repeats in TgSFI1 constitute binding sites for TgCEN1, but the binding modes of TgCEN1 to the repeats differ appreciably in terms of binding affinity, Ca<sup>2+</sup> sensitivity, and lobe-specific interaction. These results suggest that TgCEN1 displays remarkable conformational plasticity, allowing for the distinct repeats in TgSFI1 to possess precise modes of TgCEN1 binding and regulation during Ca<sup>2+</sup> sensing, which appears to be crucial for the dynamic association of TgCEN1 with TgSFI1 in the centrosome architecture. |
| first_indexed | 2024-03-09T10:00:39Z |
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| issn | 2218-273X |
| language | English |
| last_indexed | 2024-03-09T10:00:39Z |
| publishDate | 2022-08-01 |
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| record_format | Article |
| series | Biomolecules |
| spelling | doaj.art-ad433ce8ec8746a0866e0245e96fd4082023-12-01T23:29:12ZengMDPI AGBiomolecules2218-273X2022-08-01128111510.3390/biom12081115Conformational Plasticity of Centrin 1 from <i>Toxoplasma gondii</i> in Binding to the Centrosomal Protein SFI1Luca Bombardi0Filippo Favretto1Marco Pedretti2Carolina Conter3Paola Dominici4Alessandra Astegno5Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, ItalyDepartment of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, ItalyDepartment of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, ItalyDepartment of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, ItalyDepartment of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, ItalyDepartment of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, ItalyCentrins are calcium (Ca<sup>2+</sup>)-binding proteins that are involved in many cellular functions including centrosome regulation. A known cellular target of centrins is SFI1, a large centrosomal protein containing multiple repeats that represent centrin-binding motifs. Recently, a protein homologous to yeast and mammalian SFI1, denominated TgSFI1, which shares SFI1-repeat organization, was shown to colocalize at centrosomes with centrin 1 from <i>Toxoplasma gondii</i> (TgCEN1). However, the molecular details of the interaction between TgCEN1 and TgSFI1 remain largely unknown. Herein, combining different biophysical methods, including isothermal titration calorimetry, nuclear magnetic resonance, circular dichroism, and fluorescence spectroscopy, we determined the binding properties of TgCEN1 and its individual N- and C-terminal domains to synthetic peptides derived from distinct repeats of TgSFI1. Overall, our data indicate that the repeats in TgSFI1 constitute binding sites for TgCEN1, but the binding modes of TgCEN1 to the repeats differ appreciably in terms of binding affinity, Ca<sup>2+</sup> sensitivity, and lobe-specific interaction. These results suggest that TgCEN1 displays remarkable conformational plasticity, allowing for the distinct repeats in TgSFI1 to possess precise modes of TgCEN1 binding and regulation during Ca<sup>2+</sup> sensing, which appears to be crucial for the dynamic association of TgCEN1 with TgSFI1 in the centrosome architecture.https://www.mdpi.com/2218-273X/12/8/1115centrinSFI1 protein<i>Toxoplasma gondii</i>calciumprotein-peptide interactions |
| spellingShingle | Luca Bombardi Filippo Favretto Marco Pedretti Carolina Conter Paola Dominici Alessandra Astegno Conformational Plasticity of Centrin 1 from <i>Toxoplasma gondii</i> in Binding to the Centrosomal Protein SFI1 Biomolecules centrin SFI1 protein <i>Toxoplasma gondii</i> calcium protein-peptide interactions |
| title | Conformational Plasticity of Centrin 1 from <i>Toxoplasma gondii</i> in Binding to the Centrosomal Protein SFI1 |
| title_full | Conformational Plasticity of Centrin 1 from <i>Toxoplasma gondii</i> in Binding to the Centrosomal Protein SFI1 |
| title_fullStr | Conformational Plasticity of Centrin 1 from <i>Toxoplasma gondii</i> in Binding to the Centrosomal Protein SFI1 |
| title_full_unstemmed | Conformational Plasticity of Centrin 1 from <i>Toxoplasma gondii</i> in Binding to the Centrosomal Protein SFI1 |
| title_short | Conformational Plasticity of Centrin 1 from <i>Toxoplasma gondii</i> in Binding to the Centrosomal Protein SFI1 |
| title_sort | conformational plasticity of centrin 1 from i toxoplasma gondii i in binding to the centrosomal protein sfi1 |
| topic | centrin SFI1 protein <i>Toxoplasma gondii</i> calcium protein-peptide interactions |
| url | https://www.mdpi.com/2218-273X/12/8/1115 |
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