title: ERdj3 is an endoplasmic reticulum degradation factor for mutant glucocerebrosidase variants linked to Gaucher's disease.
abstract: Gaucher's disease (GD) is caused by mutations that compromise β-glucocerebrosidase (GCase) folding in the endoplasmic reticulum (ER), leading to excessive degradation instead of trafficking, which results in insufficient lysosomal function. We hypothesized that ER GCase interacting proteins play critical roles in making quality control decisions, i.e., facilitating ER-associated degradation (ERAD) instead of folding and trafficking. Utilizing GCase immunoprecipitation followed by mass-spectrometry-based proteomics, we identified endogenous HeLa cell GCase protein interactors, including ERdj3, an ER resident Hsp40 not previously established to interact with GCase. Depleting ERdj3 reduced the rate of mutant GCase degradation in patient-derived fibroblasts, while increasing folding, trafficking, and function by directing GCase to the profolding ER calnexin pathway. Inhibiting ERdj3-mediated mutant GCase degradation while simultaneously enhancing calnexin-associated folding, by way of a diltiazem-mediated increase in ER Ca(2+) levels, yields a synergistic rescue of L444P GCase lysosomal function. Our findings suggest a combination therapeutic strategy for ameliorating GD.
authors.affiliation: Departments of Chemistry and Molecular and Experimental Medicine and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Yun Lei
authors.initials: YL
authors.lastname: Tan
authors.affiliation: Departments of Chemistry and Molecular and Experimental Medicine and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Genereux
authors.affiliation: Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Sandra
authors.initials: S
authors.lastname: Pankow
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, 1105AZ Amsterdam, the Netherlands.
authors.forename: Johannes M F G
authors.initials: JM
authors.lastname: Aerts
authors.affiliation: Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Yates
authors.affiliation: Departments of Chemistry and Molecular and Experimental Medicine and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. Electronic address: jkelly@scripps.edu.
authors.forename: Jeffery W
authors.initials: JW
authors.lastname: Kelly
mesh_terms: D002478:Cells, Cultured; D004721:Endoplasmic Reticulum / Q000201:enzymology / Q000378:metabolism*; D005776:Gaucher Disease / Q000201:enzymology* / Q000235:genetics; D005962:Glucosylceramidase / Q000235:genetics* / Q000378:metabolism*; D050956:HSP40 Heat-Shock Proteins / Q000172:deficiency / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D013058:Mass Spectrometry; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D017510:Protein Folding; D040901:Proteomics
chemical_list: C494648:DNAJB11 protein, human; D050956:HSP40 Heat-Shock Proteins; D050505:Mutant Proteins; D005962:Glucosylceramidase