title: AP2 hemicomplexes contribute independently to synaptic vesicle endocytosis.
abstract: The clathrin adaptor complex AP2 is thought to be an obligate heterotetramer. We identify null mutations in the α subunit of AP2 in the nematode Caenorhabditis elegans. α-adaptin mutants are viable and the remaining μ2/β hemicomplex retains some function. Conversely, in μ2 mutants, the alpha/sigma2 hemicomplex is localized and is partially functional. α-μ2 double mutants disrupt both halves of the complex and are lethal. The lethality can be rescued by expression of AP2 components in the skin, which allowed us to evaluate the requirement for AP2 subunits at synapses. Mutations in either α or μ2 subunits alone reduce the number of synaptic vesicles by about 30%; however, simultaneous loss of both α and μ2 subunits leads to a 70% reduction in synaptic vesicles and the presence of large vacuoles. These data suggest that AP2 may function as two partially independent hemicomplexes. DOI:http://dx.doi.org/10.7554/eLife.00190.001.
authors.affiliation: Department of Biology , Howard Hughes Medical Institute, University of Utah , Salt Lake City , United States.
authors.forename: Mingyu
authors.initials: M
authors.lastname: Gu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.forename: Shigeki
authors.initials: S
authors.lastname: Watanabe
authors.forename: Lin
authors.initials: L
authors.lastname: Sun
authors.forename: Gunther
authors.initials: G
authors.lastname: Hollopeter
authors.forename: Barth D
authors.initials: BD
authors.lastname: Grant
authors.forename: Erik M
authors.initials: EM
authors.lastname: Jorgensen
mesh_terms: D033962:Adaptor Protein Complex 2 / Q000235:genetics / Q000378:metabolism*; D033965:Adaptor Protein Complex alpha Subunits / Q000235:genetics / Q000378:metabolism; D033966:Adaptor Protein Complex beta Subunits / Q000235:genetics / Q000378:metabolism; D033983:Adaptor Protein Complex mu Subunits / Q000235:genetics / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis; D005089:Exocytosis; D005838:Genotype; D010641:Phenotype; D013572:Synaptic Vesicles / Q000378:metabolism*
chemical_list: D033962:Adaptor Protein Complex 2; D033965:Adaptor Protein Complex alpha Subunits; D033966:Adaptor Protein Complex beta Subunits; D033983:Adaptor Protein Complex mu Subunits; D029742:Caenorhabditis elegans Proteins; C527887:Dpy-23 protein, C elegans
keywords: AP2; C. elegans; apa-2; apm-2; synaptic vesicle endocytosis