Effects of genetic variants in the TSPO gene on protein structure and stability.
The 18 kDa translocator protein (TSPO) is an evolutionary conserved cholesterol binding protein localized in the outer mitochondrial membrane. Expression of TSPO is upregulated in activated microglia in various neuroinflammatory, neurodegenerative, and neoplastic disorders. Therefore, TSPO radioliga...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2018-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC5895031?pdf=render |
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| author | Vladimir M Milenkovic Stefanie Bader Daniel Sudria-Lopez Ramona Siebert Caroline Brandl Caroline Nothdurfter Bernhard H F Weber Rainer Rupprecht Christian H Wetzel |
| author_facet | Vladimir M Milenkovic Stefanie Bader Daniel Sudria-Lopez Ramona Siebert Caroline Brandl Caroline Nothdurfter Bernhard H F Weber Rainer Rupprecht Christian H Wetzel |
| author_sort | Vladimir M Milenkovic |
| collection | DOAJ |
| description | The 18 kDa translocator protein (TSPO) is an evolutionary conserved cholesterol binding protein localized in the outer mitochondrial membrane. Expression of TSPO is upregulated in activated microglia in various neuroinflammatory, neurodegenerative, and neoplastic disorders. Therefore, TSPO radioligands are used as biomarkers in positron emission tomography (PET) studies. In particular, a common A147T polymorphism in the TSPO gene affects binding of several high affinity TSPO radioligands. Given the relevance of TSPO as a diagnostic biomarker in disease processes, we systematically searched for mutations in the human TSPO gene by a wide array of evolution and structure based bioinformatics tools and identified potentially deleterious missense mutations. The two most frequently observed missense mutations A147T and R162H were further analysed in structural models of human wildtype and mutant TSPO proteins. The effects of missense mutations were studied on the atomic level using molecular dynamics simulations. To analyse putative effects of A147T and R162H variants on protein stability we established primary dermal fibroblast cultures from wt and homozygous A147T and R162H donors. Stability of endogenous TSPO protein, which is abundantly expressed in fibroblasts, was studied using cycloheximide protein degradation assay. Our data show that the A147T mutation significantly alters the flexibility and stability of the mutant protein. Furthermore both A147T and R162H mutations decreased the half-life of the mutant proteins by about 25 percent, which could in part explain its effect on reduced pregnenolone production and susceptibility to neuropsychiatric disorders. The present study is the first comprehensive bioinformatic analysis of genetic variants in the TSPO gene, thereby extending the knowledge about the clinical relevance of TSPO nsSNPs. |
| first_indexed | 2024-12-10T15:40:09Z |
| format | Article |
| id | doaj.art-a54c0b37f0aa4b619a5418413b5b7cc1 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-10T15:40:09Z |
| publishDate | 2018-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-a54c0b37f0aa4b619a5418413b5b7cc12022-12-22T01:43:08ZengPublic Library of Science (PLoS)PLoS ONE1932-62032018-01-01134e019562710.1371/journal.pone.0195627Effects of genetic variants in the TSPO gene on protein structure and stability.Vladimir M MilenkovicStefanie BaderDaniel Sudria-LopezRamona SiebertCaroline BrandlCaroline NothdurfterBernhard H F WeberRainer RupprechtChristian H WetzelThe 18 kDa translocator protein (TSPO) is an evolutionary conserved cholesterol binding protein localized in the outer mitochondrial membrane. Expression of TSPO is upregulated in activated microglia in various neuroinflammatory, neurodegenerative, and neoplastic disorders. Therefore, TSPO radioligands are used as biomarkers in positron emission tomography (PET) studies. In particular, a common A147T polymorphism in the TSPO gene affects binding of several high affinity TSPO radioligands. Given the relevance of TSPO as a diagnostic biomarker in disease processes, we systematically searched for mutations in the human TSPO gene by a wide array of evolution and structure based bioinformatics tools and identified potentially deleterious missense mutations. The two most frequently observed missense mutations A147T and R162H were further analysed in structural models of human wildtype and mutant TSPO proteins. The effects of missense mutations were studied on the atomic level using molecular dynamics simulations. To analyse putative effects of A147T and R162H variants on protein stability we established primary dermal fibroblast cultures from wt and homozygous A147T and R162H donors. Stability of endogenous TSPO protein, which is abundantly expressed in fibroblasts, was studied using cycloheximide protein degradation assay. Our data show that the A147T mutation significantly alters the flexibility and stability of the mutant protein. Furthermore both A147T and R162H mutations decreased the half-life of the mutant proteins by about 25 percent, which could in part explain its effect on reduced pregnenolone production and susceptibility to neuropsychiatric disorders. The present study is the first comprehensive bioinformatic analysis of genetic variants in the TSPO gene, thereby extending the knowledge about the clinical relevance of TSPO nsSNPs.http://europepmc.org/articles/PMC5895031?pdf=render |
| spellingShingle | Vladimir M Milenkovic Stefanie Bader Daniel Sudria-Lopez Ramona Siebert Caroline Brandl Caroline Nothdurfter Bernhard H F Weber Rainer Rupprecht Christian H Wetzel Effects of genetic variants in the TSPO gene on protein structure and stability. PLoS ONE |
| title | Effects of genetic variants in the TSPO gene on protein structure and stability. |
| title_full | Effects of genetic variants in the TSPO gene on protein structure and stability. |
| title_fullStr | Effects of genetic variants in the TSPO gene on protein structure and stability. |
| title_full_unstemmed | Effects of genetic variants in the TSPO gene on protein structure and stability. |
| title_short | Effects of genetic variants in the TSPO gene on protein structure and stability. |
| title_sort | effects of genetic variants in the tspo gene on protein structure and stability |
| url | http://europepmc.org/articles/PMC5895031?pdf=render |
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