title: The LIMP-2/SCARB2 binding motif on acid β-glucosidase: basic and applied implications for Gaucher disease and associated neurodegenerative diseases.
abstract: The acid β-glucosidase (glucocerbrosidase (GCase)) binding sequence to LIMP-2 (lysosomal integral membrane protein 2), the receptor for intracellular GCase trafficking to the lysosome, has been identified. Heterologous expression of deletion constructs, the available GCase crystal structures, and binding and co-localization of identified peptides or mutant GCases were used to identify and characterize a highly conserved 11-amino acid sequence, DSPIIVDITKD, within human GCase. The binding to LIMP-2 is not dependent upon a single amino acid, but the interactions of GCase with LIMP-2 are heavily influenced by Asp(399) and the di-isoleucines, Ile(402) and Ile(403). A single alanine substitution at any of these decreases GCase binding to LIMP-2 and alters its pH-dependent binding as well as diminishing the trafficking of GCase to the lysosome and significantly increasing GCase secretion. Enterovirus 71 also binds to LIMP-2 (also known as SCARB2) on the external surface of the plasma membrane. However, the LIMP-2/SCARB2 binding sequences for enterovirus 71 and GCase are not similar, indicating that LIMP-2/SCARB2 may have multiple or overlapping binding sites with differing specificities. These findings have therapeutic implications for the production of GCase and the distribution of this enzyme that is delivered to various organs.
authors.affiliation: From the Division of Human Genetics, Cincinnati Children's Hospital Medical Center, and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45229 and.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Liou
authors.affiliation: the Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati Medical Center, Cincinnati, Ohio 45229.
authors.forename: Wendy D
authors.initials: WD
authors.lastname: Haffey
authors.affiliation: the Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati Medical Center, Cincinnati, Ohio 45229.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Greis
authors.affiliation: From the Division of Human Genetics, Cincinnati Children's Hospital Medical Center, and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45229 and greg.grabowski@cchmc.org.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Grabowski
mesh_terms: D000409:Alanine / Q000235:genetics; D000588:Amines / Q000378:metabolism; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001667:Binding, Competitive; D005776:Gaucher Disease / Q000201:enzymology* / Q000473:pathology; D005962:Glucosylceramidase / Q000737:chemistry* / Q000172:deficiency / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D047468:Immunoprecipitation; D051907:Lysosomal Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics; D019636:Neurodegenerative Diseases / Q000201:enzymology* / Q000473:pathology; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D051116:Receptors, Scavenger / Q000378:metabolism*; D014162:Transfection
chemical_list: D000588:Amines; D051907:Lysosomal Membrane Proteins; D010455:Peptides; D051116:Receptors, Scavenger; C493330:Red DND-99; C074299:SCARB2 protein, human; D049452:Green Fluorescent Proteins; D005962:Glucosylceramidase; D000409:Alanine
keywords: Enterovirus 71; Enzyme Kinetics; Glucocerebrosidase; Inborn Error of Metabolism; Intracellular Trafficking; Lysosomal Storage Disease; Lysosomal Targeting; Protein Sorting