title: Plant vacuolar trafficking occurs through distinctly regulated pathways.
abstract: The multifunctional vacuole is the largest organelle in plant cells, and many proteins are transported to and stored in this organelle; thus, the vacuole has great physiological and agronomical importance. However, the molecular mechanism and regulation of plant vacuolar traffic remain largely unknown. In this study, we demonstrate that multiple vacuolar trafficking pathways operate in plants. RAB5 and RAB7 are evolutionarily conserved subfamilies of Rab GTPase, whose animal and yeast counterparts regulate vacuolar/endosomal trafficking in a sequential manner. Functional analyses of a putative activating complex for RAB7 indicated that this complex is responsible for maturation from RAB5- to RAB7-positive endosomes in plant cells. Moreover, these machinery components are recruited to a more complex trafficking network. Mutations in RAB5 and RAB7 conferred counteracting effects on the vti11 mutant. Furthermore, impairment of RAB5- and RAB7-dependent pathways differentially affected the transport of distinctive cargos. These results indicate that plants have developed a complex vacuolar transport system distinct from that of nonplant systems by assigning evolutionarily conserved machinery to unique trafficking pathways. These pathways provide a fundamental basis for plant development at the cellular and higher-ordered levels.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ebine
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0101, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Ito
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Ito
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Uemura
authors.affiliation: Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan.
authors.forename: Tatsuaki
authors.initials: T
authors.lastname: Goh
authors.affiliation: Antibiotics Laboratory, RIKEN, and RIKEN Center for Sustainable Resource Science (CSRS), Gene Discovery Research Group, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Abe
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; RIKEN Center for Advanced Photonics, Live Cell Molecular Imaging Research Team, Extreme Photonics Research Group, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nakano
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan. Electronic address: tueda@bs.s.u-tokyo.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ueda
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D001692:Biological Transport; D011992:Endosomes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D021381:Protein Transport; D014617:Vacuoles / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins