Skip to main content
. Author manuscript; available in PMC: 2010 Mar 6.
Published in final edited form as: Curr Opin Cell Biol. 2008 May 9;20(4):427–436. doi: 10.1016/j.ceb.2008.03.009

Figure 1.

Figure 1

Sorting of acid hydrolases mediated by mannose 6-phosphate receptors. The scheme represents the sorting of acid hydrolases by transmembrane, mannose 6-phosphate receptors (MPR) that cycle between the trans-Golgi network (TGN) and endosomes. Coats containing clathrin, GGA and AP-1 mediate exit of hydrolase-MPR complexes from the TGN, whereas retromer mediates the retrieval of unoccupied MPR from endosomes. Sequestration of MPR into recycling tubules by retromer prevents their delivery to the degradative, multivesicular body (MVB) pathway by the clathrin-ESCRT machinery. A fraction of MPR are transported from the TGN to the plasma membrane, after which they are internalized by coats containing clathrin and AP-2, joining the pool of recycling receptors in endosomes. See text for additional details and references. TEN: tubular endosomal network; H+ represents the acidic pH of the endosome lumen.