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Sorting nexin 17 facilitates LRP recycling in the early endosome
Author(s) -
van Kerkhof Peter,
Lee Jiyeon,
McCormick Lynn,
Tetrault Elena,
Lu Wenyan,
Schoenfish Marissa,
Oorschot Viola,
Strous Ger J,
Klumperman Judith,
Bu Guojun
Publication year - 2005
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7600756
Subject(s) - st louis , medical school , library science , medicine , history , medical education , art history , computer science
The low‐density lipoprotein (LDL) receptor‐related protein (LRP) is a multiligand endocytic receptor and a member of the LDL receptor family. Here we show that sorting nexin 17 (Snx17) is part of the cellular sorting machinery that regulates cell surface levels of LRP by promoting its recycling. While the phox (PX) domain of Snx17 interacts with phosphatidylinositol‐3‐phosphate for membrane association, the FERM domain and the carboxyl‐terminal region participate in LRP binding. Immunoelectron microscopy shows that the membrane‐bound fraction of Snx17 is localized to the limiting membrane and recycling tubules of early endosomes. The NPxY motif, proximal to the plasma membrane in the LRP cytoplasmic tail, is identified as the Snx17‐binding motif. Functional mutation of this motif did not interfere with LRP endocytosis, but decreased LRP recycling from endosomes, resulting in increased lysosomal degradation. Similar effects are found after knockdown of endogenous Snx17 expression by short interfering RNA. We conclude that Snx17 binds to a motif in the LRP tail distinct from the endocytosis signals and promotes LRP sorting to the recycling pathway in the early endosomes.