The primary familial brain calcification-associated protein MYORG is an α-galactosidase with restricted substrate specificity.

Autor: Meek RW; Department of Chemistry. University of York, York, United Kingdom., Brockerman J; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.; Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada., Fordwour OB; Department of Chemistry, Irving K. Barber Faculty of Science, University of British Columbia, Kelowna, British Columbia, Canada., Zandberg WF; Department of Chemistry, Irving K. Barber Faculty of Science, University of British Columbia, Kelowna, British Columbia, Canada., Davies GJ; Department of Chemistry. University of York, York, United Kingdom., Vocadlo DJ; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.; Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada.
Jazyk: angličtina
Zdroj: PLoS biology [PLoS Biol] 2022 Sep 21; Vol. 20 (9), pp. e3001764. Date of Electronic Publication: 2022 Sep 21 (Print Publication: 2022).
DOI: 10.1371/journal.pbio.3001764
Abstrakt: Primary familial brain calcification (PFBC) is characterised by abnormal deposits of calcium phosphate within various regions of the brain that are associated with severe cognitive impairments, psychiatric conditions, and movement disorders. Recent studies in diverse populations have shown a link between mutations in myogenesis-regulating glycosidase (MYORG) and the development of this disease. MYORG is a member of glycoside hydrolase (GH) family 31 (GH31) and, like the other mammalian GH31 enzyme α-glucosidase II, this enzyme is found in the lumen of the endoplasmic reticulum (ER). Though presumed to act as an α-glucosidase due to its localization and sequence relatedness to α-glucosidase II, MYORG has never been shown to exhibit catalytic activity. Here, we show that MYORG is an α-galactosidase and present the high-resolution crystal structure of MYORG in complex with substrate and inhibitor. Using these structures, we map detrimental mutations that are associated with MYORG-associated brain calcification and define how these mutations may drive disease progression through loss of enzymatic activity. Finally, we also detail the thermal stabilisation of MYORG afforded by a clinically approved small molecule ligand, opening the possibility of using pharmacological chaperones to enhance the activity of mutant forms of MYORG.
Competing Interests: The authors have declared that no competing interests exist.
Databáze: MEDLINE
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