title: MTV1 and MTV4 encode plant-specific ENTH and ARF GAP proteins that mediate clathrin-dependent trafficking of vacuolar cargo from the trans-Golgi network.
abstract: Many soluble proteins transit through the trans-Golgi network (TGN) and the prevacuolar compartment (PVC) en route to the vacuole, but our mechanistic understanding of this vectorial trafficking step in plants is limited. In particular, it is unknown whether clathrin-coated vesicles (CCVs) participate in this transport step. Through a screen for modified transport to the vacuole (mtv) mutants that secrete the vacuolar protein VAC2, we identified MTV1, which encodes an epsin N-terminal homology protein, and MTV4, which encodes the ADP ribosylation factor GTPase-activating protein nevershed/AGD5. MTV1 and NEV/AGD5 have overlapping expression patterns and interact genetically to transport vacuolar cargo and promote plant growth, but they have no apparent roles in protein secretion or endocytosis. MTV1 and NEV/AGD5 colocalize with clathrin at the TGN and are incorporated into CCVs. Importantly, mtv1 nev/agd5 double mutants show altered subcellular distribution of CCV cargo exported from the TGN. Moreover, MTV1 binds clathrin in vitro, and NEV/AGD5 associates in vivo with clathrin, directly linking these proteins to CCV formation. These results indicate that MTV1 and NEV/AGD5 are key effectors for CCV-mediated trafficking of vacuolar proteins from the TGN to the PVC in plants.
authors.affiliation: Departamento Molecular de Plantas, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Cientificas, 28049 Madrid, Spain.
authors.forename: Michael
authors.initials: M
authors.lastname: Sauer
authors.forename: M Otilia
authors.initials: MO
authors.lastname: Delgadillo
authors.forename: Jan
authors.initials: J
authors.lastname: Zouhar
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Reynolds
authors.forename: Janice G
authors.initials: JG
authors.lastname: Pennington
authors.forename: Liwen
authors.initials: L
authors.lastname: Jiang
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Liljegren
authors.forename: York-Dieter
authors.initials: YD
authors.lastname: Stierhof
authors.forename: Geert
authors.initials: G
authors.lastname: De Jaeger
authors.forename: Marisa S
authors.initials: MS
authors.lastname: Otegui
authors.forename: Sebastian Y
authors.initials: SY
authors.lastname: Bednarek
authors.forename: Enrique
authors.initials: E
authors.lastname: Rojo
mesh_terms: D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002966:Clathrin / Q000378:metabolism*; D020690:GTPase-Activating Proteins; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D018519:Meristem / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D030821:Plants, Genetically Modified; D011485:Protein Binding; D021381:Protein Transport / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014617:Vacuoles / Q000378:metabolism* / Q000648:ultrastructure; D021601:trans-Golgi Network / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D002966:Clathrin; D020690:GTPase-Activating Proteins; C586774:MTV1 protein, Arabidopsis; C544765:NEV protein, Arabidopsis; D049452:Green Fluorescent Proteins