title: Functional analysis of interaction sites on the N-terminal domain of clathrin heavy chain.
abstract: In clathrin-mediated membrane traffic, clathrin does not bind directly to cargo and instead binds to adaptors that mediate this function. For endocytosis, the main adaptor is the adaptor protein (AP)-2 complex, but it is uncertain how clathrin contacts AP-2. Here we tested in human cells the importance of the three binding sites that have been identified so far on the N-terminal domain (NTD) of clathrin. We find that mutation of each of the three sites on the NTD, alone or in combination, does not block clathrin/AP-2-mediated endocytosis in the same way as deletion of the NTD. We report here the fourth and final site on the NTD that is required for clathrin/AP-2-mediated endocytic function. Each of the four interaction sites can operate alone to mediate endocytosis. The observed functional redundancy between interaction sites on the NTD explains how productivity of clathrin-coated vesicle formation is ensured.
authors.affiliation: The Physiological Laboratory, University of Liverpool, Crown Street, Liverpool, United Kingdom.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Willox
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Royle
mesh_terms: D033962:Adaptor Protein Complex 2 / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism*; D033922:Clathrin Heavy Chains / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014162:Transfection
chemical_list: D033962:Adaptor Protein Complex 2; D011993:Recombinant Fusion Proteins; D033922:Clathrin Heavy Chains; D049452:Green Fluorescent Proteins