Download MendeleyLysosome sorting of beta-glucocerebrosidase by LIMP-2 is targeted by the mannose 6-phosphate receptor.
Zhao, Y., Ren, J., Padilla-Parra, S., Fry, E.E., Stuart, D.I.(2014) Nat Commun 5: 4321-4321
- PubMed: 25027712
- DOI: https://doi.org/10.1038/ncomms5321
- Primary Citation of Related Structures:
4Q4B, 4Q4F - PubMed Abstract:
The integral membrane protein LIMP-2 has been a paradigm for mannose 6-phosphate receptor (MPR) independent lysosomal targeting, binding to β-glucocerebrosidase (β-GCase) and directing it to the lysosome, before dissociating in the late-endosomal/lysosomal compartments. Here we report structural results illuminating how LIMP-2 binds and releases β-GCase according to changes in pH, via a histidine trigger, and suggesting that LIMP-2 localizes the ceramide portion of the substrate adjacent to the β-GCase catalytic site. Remarkably, we find that LIMP-2 bears P-Man9GlcNAc2 covalently attached to residue N325, and that it binds MPR, via mannose 6-phosphate, with a similar affinity to that observed between LIMP-2 and β-GCase. The binding sites for β-GCase and the MPR are functionally separate, so that a stable ternary complex can be formed. By fluorescence lifetime imaging microscopy, we also demonstrate that LIMP-2 interacts with MPR in living cells. These results revise the accepted view of LIMP-2-β-GCase lysosomal targeting.
Organizational Affiliation:
1] Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford OX3 7BN, UK [2].
