title: Coupling of vesicle tethering and Rab binding is required for in vivo functionality of the golgin GMAP-210.
abstract: Golgins are extended coiled-coil proteins believed to participate in membrane-tethering events at the Golgi apparatus. However, the importance of golgin-mediated tethering remains poorly defined, and alternative functions for golgins have been proposed. Moreover, although golgins bind to Rab GTPases, the functional significance of Rab binding has yet to be determined. In this study, we show that depletion of the golgin GMAP-210 causes a loss of Golgi cisternae and accumulation of numerous vesicles. GMAP-210 function in vivo is dependent upon its ability to tether membranes, which is mediated exclusively by the amino-terminal ALPS motif. Binding to Rab2 is also important for GMAP-210 function, although it is dispensable for tethering per se. GMAP-210 length is also functionally important in vivo. Together our results indicate a key role for GMAP-210-mediated membrane tethering in maintaining Golgi structure and support a role for Rab2 binding in linking tethering with downstream docking and fusion events at the Golgi apparatus.
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sato
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Peristera
authors.initials: P
authors.lastname: Roboti
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Mironov
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom martin.lowe@manchester.ac.uk.
authors.forename: Martin
authors.initials: M
authors.lastname: Lowe
mesh_terms: D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D003598:Cytoskeletal Proteins; D006056:Golgi Apparatus / Q000502:physiology*; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020693:rab2 GTP-Binding Protein / Q000378:metabolism*
chemical_list: D003598:Cytoskeletal Proteins; D009687:Nuclear Proteins; C109331:TRIP11 protein, human; D020693:rab2 GTP-Binding Protein