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The pharmacological chaperone 1‐deoxynojirimycin increases the activity and lysosomal trafficking of multiple mutant forms of acid alpha‐glucosidase
Author(s) -
Flanagan John J.,
Rossi Barbara,
Tang Katherine,
Wu Xiaoyang,
Mascioli Kirsten,
Donaudy Francesca,
Tuzzi Maria Rosaria,
Fontana Federica,
Cubellis Maria Vittoria,
Porto Caterina,
Benjamin Elfrida,
Lockhart David J.,
Valenzano Kenneth J.,
Andria Generoso,
Parenti Giancarlo,
Do Hung V.
Publication year - 2009
Publication title -
human mutation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 162
eISSN - 1098-1004
pISSN - 1059-7794
DOI - 10.1002/humu.21121
Subject(s) - mutant , biology , chemical chaperone , fabry disease , transfection , enzyme , biochemistry , lysosomal storage disease , microbiology and biotechnology , chaperone (clinical) , hek 293 cells , mutant protein , gene , disease , medicine , pathology
Pompe disease is a lysosomal storage disorder (LSD) caused by mutations in the gene that encodes acid α‐glucosidase (GAA). Recently, small molecule pharmacological chaperones have been shown to increase protein stability and cellular levels for mutant lysosomal enzymes and have emerged as a new therapeutic strategy for the treatment of LSDs. In this study, we characterized the pharmacological chaperone 1‐deoxynojirimycin (DNJ) on 76 different mutant forms of GAA identified in Pompe disease. DNJ significantly increased enzyme activity and protein levels for 16 different GAA mutants in patient‐derived fibroblasts and in transiently transfected COS‐7 cells. Additionally, DNJ increased the processing of these GAA mutants to their mature lysosomal forms, suggesting facilitated trafficking through the secretory pathway. Immunofluorescence microscopy studies showed increased colocalization of GAA with the lysosomal marker LAMP2 after incubation with DNJ, confirming increased lysosomal trafficking. Lastly, a GAA structural model was constructed based on the related eukaryotic glucosidase maltase‐glucoamylase. The mutated residues identified in responsive forms of GAA are located throughout most of the structural domains, with half of these residues located in two short regions within the catalytic domain. Taken together, these data support further evaluation of DNJ as a potential treatment for Pompe disease in patients that express responsive forms of GAA. Hum Mutat 30:1–10, 2009. © 2009 Wiley‐Liss, Inc.