Molecular Characterization of Mutations That Cause Globoid Cell Leukodystrophy and Pharmacological Rescue Using Small Molecule Chemical Chaperones

摘要: Globoid cell leukodystrophy (GLD) (Krabbe disease) is an autosomal recessive, degenerative, lysosomal storage disease caused by a severe loss of galactocerebrosidase (GALC) enzymatic activity. Of the >70 disease-causing mutations in GALC gene, most are located outside catalytic domain enzyme. To determine how impair activity, we investigated impact multiple on processing, localization, and Studies mammalian cells revealed dramatic decreases activity lack appropriate protein processing into N-terminal fragment for each mutants examined. Consistent with this, observed significantly less localized to lysosome impairment either secretion or reuptake mutant GALC. Notably, D528N mutation was found induce hyperglycosylation misfolding. Reversal these conditions resulted increase proper suggesting that glycosylation may play critical role process patients this mutation. Recent studies have shown enzyme inhibitors can sometimes "chaperone" misfolded polypeptides their target organelle, bypassing normal cellular quality control machinery resulting enhanced whether also work GLD, examined effect alpha-lobeline, inhibitor GALC, cells. After treatment, increased. This study suggests cause GLD impairing and/or folding pharmacological chaperones be potential therapeutic agents carrying certain mutations.