title: The AtVAM3 encodes a syntaxin-related molecule implicated in the vacuolar assembly in Arabidopsis thaliana.
abstract: The vacuole constitutes a large compartment in plant and fungal cells. The VAM3 gene of Saccharomyces cerevisiae encodes a syntaxin-related protein required for vacuolar assembly. An Arabidopsis thaliana cDNA library, designed for expression in S. cerevisiae, was screened for cDNAs able to complement defective vacuolar assembly of the Deltavam3 mutation. One cDNA, encoding a 33-kDa protein with structural similarities to the other syntaxins, was identified. The product of AtVAM3 (AtVam3p) was expressed in various tissues including roots, leaves, inflorescence stems, flower buds, and young siliques. The AtVAM3 transcripts were abundant in undifferentiated cells in the meristematic region. AtVam3p fractionated predominantly to an 8,000 x g pellet fraction where a vacuolar membrane protein H+-translocating inorganic pyrophosphatase (H+-PPase) also fractionated. Immunoelectron microscopy showed that AtVam3p was localized to restricted regions on the vacuolar membranes. We propose that AtVam3p provides the t-SNARE function in the vacuolar assembly in A. thaliana.
authors.affiliation: Department of Biology, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Tokyo 153, Japan.
authors.forename: M H
authors.initials: MH
authors.lastname: Sato
authors.forename: N
authors.initials: N
authors.lastname: Nakamura
authors.forename: Y
authors.initials: Y
authors.lastname: Ohsumi
authors.forename: H
authors.initials: H
authors.lastname: Kouchi
authors.forename: M
authors.initials: M
authors.lastname: Kondo
authors.forename: I
authors.initials: I
authors.lastname: Hara-Nishimura
authors.forename: M
authors.initials: M
authors.lastname: Nishimura
authors.forename: Y
authors.initials: Y
authors.lastname: Wada
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics*; D050765:Qa-SNARE Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014617:Vacuoles / Q000378:metabolism*
chemical_list: C489890:ATPEP12 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D008565:Membrane Proteins; C081224:PEP12 protein, S cerevisiae; D010940:Plant Proteins; D050765:Qa-SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; C108430:Vam3 protein, Arabidopsis