A critical histidine residue within LIMP-2 mediates pH sensitive binding to its ligand β-glucocerebrosidase

Traffic. 2012 Aug;13(8):1113-23. doi: 10.1111/j.1600-0854.2012.01372.x. Epub 2012 May 15.

Abstract

The lysosomal membrane protein type 2 is a novel identified lysosomal sorting receptor for β-glucocerebrosidase (GC). Mutations in both genes underlie human pathologies causing action myoclonus-renal failure syndrome (AMRF) and Gaucher disease (GD), respectively. We now demonstrate that the lumenal acidification mediated by the vacuolar (H(+) )-ATPase triggers the dissociation of LIMP-2 and GC in late endosomal/lysosomal compartments. Moreover, we identified a single histidine residue in LIMP-2 that is necessary for LIMP-2 and GC binding. This residue is in close proximity to a proposed coiled-coil domain, which determines the binding to GC and may function as a critical pH sensor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Cells, Cultured
  • Chlorocebus aethiops
  • Codon, Nonsense
  • Endosomes / enzymology
  • Endosomes / metabolism
  • Enzyme Inhibitors / pharmacology
  • Fibroblasts / metabolism
  • Glucosylceramidase / metabolism*
  • HeLa Cells
  • Histidine / chemistry*
  • Humans
  • Hydrogen-Ion Concentration
  • Lysosomal Membrane Proteins / chemistry*
  • Lysosomal Membrane Proteins / genetics*
  • Lysosomal Membrane Proteins / metabolism
  • Lysosomes / enzymology
  • Lysosomes / metabolism
  • Macrolides / pharmacology
  • Mice
  • Molecular Sequence Data
  • Mutation, Missense
  • Myoclonic Epilepsies, Progressive / genetics
  • Protein Binding / genetics
  • Receptors, Scavenger / chemistry*
  • Receptors, Scavenger / genetics*
  • Receptors, Scavenger / metabolism
  • Vacuolar Proton-Translocating ATPases / antagonists & inhibitors
  • Vacuolar Proton-Translocating ATPases / metabolism

Substances

  • Codon, Nonsense
  • Enzyme Inhibitors
  • Lysosomal Membrane Proteins
  • Macrolides
  • Receptors, Scavenger
  • SCARB2 protein, human
  • Histidine
  • bafilomycin A1
  • Glucosylceramidase
  • Vacuolar Proton-Translocating ATPases