The Mammalian AP-3 Adaptor-like Complex Mediates the Intracellular Transport of Lysosomal Membrane Glycoproteins

Roland Le Borgne, Agustin Alconada, Ulrike Bauer, Bernard Hoflack
1998 Journal of Biological Chemistry  
In mammalian cells, the mannose 6-phosphate receptors (MPRs) and the lysosomal glycoproteins, lysosomalassociated membrane protein (LAMP) I, lysosomal integral membrane protein (LIMP) II, are directly transported from the trans-Golgi network to endosomes and lysosomes. While MPR traffic relies on the AP-1 adaptor complex, we report that proper targeting of LAMP I and LIMP II to lysosomes requires the AP-3 adaptor-like complex. Overexpression of these proteins, which contain either a tyrosine-or
more » ... a di-leucine-basedsorting motif, promotes AP-3 recruitment on membranes. Inhibition of AP-3 function using antisense oligonucleotides leads to a selective misrouting of both LAMP I and LIMP II to the cell surface without affecting MPR trafficking. These results provide evidence that AP-3 functions in the intracellular targeting of transmembrane glycoproteins to lysosomes.
doi:10.1074/jbc.273.45.29451 pmid:9792650 fatcat:2yolvipxmfby5ht6zhxjs2w7ba