title: Syp1 is a conserved endocytic adaptor that contains domains involved in cargo selection and membrane tubulation.
abstract: Internalization of diverse transmembrane cargos from the plasma membrane requires a similarly diverse array of specialized adaptors, yet only a few adaptors have been characterized. We report the identification of the muniscin family of endocytic adaptors that is conserved from yeast to human beings. Solving the structures of yeast muniscin domains confirmed the unique combination of an N-terminal domain homologous to the crescent-shaped membrane-tubulating EFC/F-BAR domains and a C-terminal domain homologous to cargo-binding mu homology domains (muHDs). In vitro and in vivo assays confirmed membrane-tubulation activity for muniscin EFC/F-BAR domains. The muHD domain has conserved interactions with the endocytic adaptor/scaffold Ede1/eps15, which influences muniscin localization. The transmembrane protein Mid2, earlier implicated in polarized Rho1 signalling, was identified as a cargo of the yeast adaptor protein. These and other data suggest a model in which the muniscins provide a combined adaptor/membrane-tubulation activity that is important for regulating endocytosis.
authors.affiliation: Department of Biology, The Johns Hopkins University, Baltimore, MD 21218-2685, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Reider
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Barker
authors.forename: Sanjay K
authors.initials: SK
authors.lastname: Mishra
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Im
authors.forename: Lymarie
authors.initials: L
authors.lastname: Maldonado-Báez
authors.forename: James H
authors.initials: JH
authors.lastname: Hurley
authors.forename: Linton M
authors.initials: LM
authors.lastname: Traub
authors.forename: Beverly
authors.initials: B
authors.lastname: Wendland
mesh_terms: D004705:Endocytosis / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: C510360:Ede1 protein, S cerevisiae; C524557:FCHO1 protein, human; D008565:Membrane Proteins; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins