4afi
Complex between Vamp7 longin domain and fragment of delta-adaptin from AP3Complex between Vamp7 longin domain and fragment of delta-adaptin from AP3
Structural highlights
FunctionAP3D1_HUMAN Part of the AP-3 complex, an adaptor-related complex which is not clathrin-associated. The complex is associated with the Golgi region as well as more peripheral structures. It facilitates the budding of vesicles from the Golgi membrane and may be directly involved in trafficking to lysosomes. In concert with the BLOC-1 complex, AP-3 is required to target cargos into vesicles assembled at cell bodies for delivery into neurites and nerve terminals.VAMP7_MOUSE Involved in the targeting and/or fusion of transport vesicles to their target membrane during transport of proteins from the early endosome to the lysosome. Required for heterotypic fusion of late endosomes with lysosomes and homotypic lysosomal fusion. Required for calcium regulated lysosomal exocytosis. Involved in the export of chylomicrons from the endoplasmic reticulum to the cis Golgi. Required for exocytosis of mediators during eosinophil and neutrophil degranulation, and target cell killing by natural killer cells. Required for focal exocytosis of late endocytic vesicles during phagosome formation.[1] Publication Abstract from PubMedVAMP7 is involved in the fusion of late endocytic compartments with other membranes. One possible mechanism of VAMP7 delivery to these late compartments is via the AP3 trafficking adaptor. We show that the linker of the delta-adaptin subunit of AP3 binds the VAMP7 longin domain and determines the structure of their complex. Mutation of residues on both partners abolishes the interaction in vitro and in vivo. The binding of VAMP7 to delta-adaptin requires the VAMP7 SNARE motif to be engaged in SNARE complex formation and hence AP3 must transport VAMP7 when VAMP7 is part of a cis-SNARE complex. The absence of delta-adaptin causes destabilization of the AP3 complex in mouse mocha fibroblasts and mislocalization of VAMP7. The mislocalization can be rescued by transfection with wild-type delta-adaptin but not by delta-adaptin containing mutations that abolish VAMP7 binding, despite in all cases intact AP3 being present and LAMP1 trafficking being rescued. Structural basis of the intracellular sorting of the SNARE VAMP7 by the AP3 adaptor complex.,Kent HM, Evans PR, Schafer IB, Gray SR, Sanderson CM, Luzio JP, Peden AA, Owen DJ Dev Cell. 2012 May 15;22(5):979-88. Epub 2012 Apr 19. PMID:22521722[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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