title: Loss of glucocerebrosidase 1 activity causes lysosomal dysfunction and α-synuclein aggregation.
abstract: Lysosomal dysfunction is a common pathological feature of neurodegenerative diseases. GTP-binding protein type A1 (GBA1) encodes β-glucocerebrosidase 1 (GCase 1), a lysosomal hydrolase. Homozygous mutations in GBA1 cause Gaucher disease, the most common lysosomal storage disease, while heterozygous mutations are strong risk factors for Parkinson's disease. However, whether loss of GCase 1 activity is sufficient for lysosomal dysfunction has not been clearly determined. Here, we generated human neuroblastoma cell lines with nonsense mutations in the GBA1 gene using zinc-finger nucleases. Depending on the site of mutation, GCase 1 activity was lost or maintained. The cell line with GCase 1 deficiency showed indications of lysosomal dysfunction, such as accumulation of lysosomal substrates, reduced dextran degradation and accumulation of enlarged vacuolar structures. In contrast, the cell line with C-terminal truncation of GCase 1 but with intact GCase 1 activity showed normal lysosomal function. When α-synuclein was overexpressed, accumulation and secretion of insoluble aggregates increased in cells with GCase 1 deficiency but did not change in mutant cells with normal GCase 1 activity. These results demonstrate that loss of GCase 1 activity is sufficient to cause lysosomal dysfunction and accumulation of α-synuclein aggregates.
authors: 1] Department of Biomedical Science and Technology, Konkuk University, Seoul, Korea [2] Institute of Biomedical Science and Technology, Konkuk University, Seoul, Korea.
authors: Eun-Jin
authors: EJ
authors: Bae
authors: 1] Department of Biomedical Science and Technology, Konkuk University, Seoul, Korea [2] Institute of Biomedical Science and Technology, Konkuk University, Seoul, Korea.
authors: Na Young
authors: NY
authors: Yang
authors: 1] Institute of Biomedical Science and Technology, Konkuk University, Seoul, Korea [2] Department of Anatomy, School of Medicine, Konkuk University, Seoul, Korea.
authors: Cheolsoon
authors: C
authors: Lee
authors: 1] Institute of Biomedical Science and Technology, Konkuk University, Seoul, Korea [2] Department of Anatomy, School of Medicine, Konkuk University, Seoul, Korea.
authors: He-Jin
authors: HJ
authors: Lee
authors: ToolGen, Biotechnology Incubating Center, Seoul National University, Seoul, Korea.
authors: Seokjoong
authors: S
authors: Kim
authors: Genzyme, Framingham, MA, USA.
authors: Sergio Pablo
authors: SP
authors: Sardi
authors: 1] Department of Biomedical Science and Technology, Konkuk University, Seoul, Korea [2] Institute of Biomedical Science and Technology, Konkuk University, Seoul, Korea [3] College of Veterinary Medicine, Konkuk University, Seoul, Korea.
authors: Seung-Jae
authors: SJ
authors: Lee
mesh_terms: D002460:Cell Line; D004789:Enzyme Activation / Q000235:genetics; D055786:Gene Knockout Techniques; D023061:Gene Order; D056426:Genetic Loci; D005962:Glucosylceramidase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008247:Lysosomes / Q000378:metabolism*; D009154:Mutation; D066263:Protein Aggregation, Pathological / Q000235:genetics; D011485:Protein Binding; D016335:Zinc Fingers; D051844:alpha-Synuclein / Q000737:chemistry / Q000378:metabolism*
chemical_list: D051844:alpha-Synuclein; D005962:Glucosylceramidase