title: Functional homologies in vesicle tethering.
abstract: The HOPS multisubunit tethering factor (MTC) is a macromolecular protein complex composed of six different subunits. It is one of the key components in the perception and subsequent fusion of multivesicular bodies and vacuoles. Electron microscopy studies indicate structural flexibility of the purified HOPS complex. Inducing higher rigidity into HOPS by biochemically modifying the complex declines the potential to mediate SNARE-driven membrane fusion. Thus, we propose that integral flexibility seems to be not only a feature, but of essential need for the function of HOPS. This review focuses on the general features of membrane tethering and fusion. For this purpose, we compare the structure and mode of action of different tethering factors to highlight their common central features and mechanisms.
authors.affiliation: Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany. Electronic address: anne.kuhlee@mpi-dortmund.mpg.de.
authors.forename: Anne
authors.initials: A
authors.lastname: Kuhlee
authors.affiliation: Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Raunser
authors.affiliation: Department of Biology, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Ungermann
mesh_terms: D000595:Amino Acid Sequence; D006801:Humans; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D057146:Multivesicular Bodies / Q000378:metabolism*; D011485:Protein Binding; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D017386:Sequence Homology, Amino Acid
chemical_list: D046912:Multiprotein Complexes; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins
keywords: HOPS; Protein complex; Structural flexibility; Tethering; Vesicle