1. Academic Validation
  2. The molecular basis for the endocytosis of small R-SNAREs by the clathrin adaptor CALM

The molecular basis for the endocytosis of small R-SNAREs by the clathrin adaptor CALM

  • Cell. 2011 Nov 23;147(5):1118-31. doi: 10.1016/j.cell.2011.10.038.
Sharon E Miller 1 Daniela A Sahlender Stephen C Graham Stefan Höning Margaret S Robinson Andrew A Peden David J Owen
Affiliations

Affiliation

  • 1 Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, UK.
Abstract

SNAREs provide a large part of the specificity and energy needed for membrane fusion and, to do so, must be localized to their correct membranes. Here, we show that the R-SNAREs VAMP8, VAMP3, and VAMP2, which cycle between the plasma membrane and endosomes, bind directly to the ubiquitously expressed, PtdIns4,5P(2)-binding, endocytic clathrin adaptor CALM/PICALM. X-ray crystallography shows that the N-terminal halves of their SNARE motifs bind the CALM(ANTH) domain as helices in a manner that mimics SNARE complex formation. Mutation of residues in the CALM:SNARE interface inhibits binding in vitro and prevents R-SNARE endocytosis in vivo. Thus, CALM:R-SNARE interactions ensure that R-SNAREs, required for the fusion of endocytic clathrin-coated vesicles with endosomes and also for subsequent postendosomal trafficking, are sorted into endocytic vesicles. CALM's role in directing the endocytosis of small R-SNAREs may provide insight into the association of CALM/PICALM mutations with growth retardation, cognitive defects, and Alzheimer's disease.

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