Effects of genetic variants in the TSPO gene on protein structure and stability

Milenkovic, Vladimir M. and Bader, Stefanie and Sudria-Lopez, Daniel and Siebert, Ramona and Brandl, Caroline and Nothdurfter, Caroline and Weber, Bernhard H. F. and Rupprecht, Rainer and Wetzel, Christian H. (2018) Effects of genetic variants in the TSPO gene on protein structure and stability. PLOS ONE, 13 (4): e0195627. ISSN 1932-6203,

Full text not available from this repository. (Request a copy)

Abstract

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.

Item Type: Article
Uncontrolled Keywords: MITOCHONDRIAL TRANSLOCATOR PROTEIN; POSITRON-EMISSION-TOMOGRAPHY; AMINO-ACID SUBSTITUTIONS; 18 KDA TSPO; PERIPHERAL BENZODIAZEPINE; DELETERIOUS MUTATIONS; SYNONYMOUS VARIANTS; A147T POLYMORPH; BINDING; AFFINITY;
Subjects: 600 Technology > 610 Medical sciences Medicine
Divisions: Medicine > Lehrstuhl für Psychiatrie und Psychotherapie
Depositing User: Dr. Gernot Deinzer
Date Deposited: 10 Mar 2020 13:13
Last Modified: 10 Mar 2020 13:13
URI: https://pred.uni-regensburg.de/id/eprint/14730

Actions (login required)

View Item View Item