title: Systematic analysis of SNARE molecules in Arabidopsis: dissection of the post-Golgi network in plant cells.
abstract: In all eucaryotic cells, specific vesicle fusion during vesicular transport is mediated by membrane-associated proteins called SNAREs (soluble N-ethyl-maleimide sensitive factor attachment protein receptors). Sequence analysis identified a total of 54 SNARE genes (18 Qa-SNAREs/Syntaxins, 11 Qb-SNAREs, 8 Qc-SNAREs, 14 R-SNAREs/VAMPs and 3 SNAP-25) in the Arabidopsis genome. Almost all of them were ubiquitously expressed through out all tissues examined. A series of transient expression assays using green fluorescent protein (GFP) fused proteins revealed that most of the SNARE proteins were located on specific intracellular compartments: 6 in the endoplasmic reticulum, 9 in the Golgi apparatus, 4 in the trans-Golgi network (TGN), 2 in endosomes, 17 on the plasma membrane, 7 in both the prevacuolar compartment (PVC) and vacuoles, 2 in TGN/PVC/vacuoles, and 1 in TGN/PVC/plasma membrane. Some SNARE proteins showed multiple localization patterns in two or more different organelles, suggesting that these SNAREs shuttle between the organelles. Furthermore, the SYP41/SYP61-residing compartment, which was defined as the TGN, was not always located along with the Golgi apparatus, suggesting that this compartment is an independent organelle distinct from the Golgi apparatus. We propose possible combinations of SNARE proteins on all subcellular compartments, and suggest the complexity of the post-Golgi membrane traffic in higher plant cells.
authors.affiliation: Graduate School of Biostudies, Kyoto University, Yoshida-nihonmatsu, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Uemura
authors.forename: Takashi
authors.initials: T
authors.lastname: Ueda
authors.forename: Ryosuke L
authors.initials: RL
authors.lastname: Ohniwa
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nakano
authors.forename: Kunio
authors.initials: K
authors.lastname: Takeyasu
authors.forename: Masa H
authors.initials: MH
authors.lastname: Sato
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D020869:Gene Expression Profiling; D017343:Genes, Plant / Q000235:genetics; D006056:Golgi Apparatus / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D050683:R-SNARE Proteins; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D050600:SNARE Proteins; D016415:Sequence Alignment; D014617:Vacuoles / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D008565:Membrane Proteins; D050683:R-SNARE Proteins; D012333:RNA, Messenger; D050600:SNARE Proteins; D033921:Vesicular Transport Proteins