title: AtVPS29, a putative component of a retromer complex, is required for the efficient sorting of seed storage proteins.
abstract: Seed storage proteins are synthesized on rough endoplasmic reticulum (ER) as larger precursors and are sorted to protein storage vacuoles, where they are converted into the mature forms. We report here an Arabidopsis mutant, maigo 1 (mag1), which abnormally accumulates the precursors of two major storage proteins, 12S globulin and 2S albumin, in dry seeds. Electron microscopy revealed that mag1 seeds mis-sort storage proteins by secreting them from cells. mag1 seeds have smaller protein storage vacuoles in the seeds than do wild-type seeds. The MAG1 gene encodes a homolog of the yeast (Saccharomyces cerevisiae) protein VPS29. VPS29 is a component of a retromer complex for recycling a vacuolar sorting receptor VPS10 from the pre-vacuolar compartment to the Golgi complex. Our findings suggest that MAG1/AtVPS29 protein is involved in recycling a plant receptor for the efficient sorting of seed storage proteins. The mag1 mutant exhibits a dwarf phenotype. A plant retromer complex plays a significant role in plant growth and development.
authors.affiliation: Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan.
authors.forename: Tomoo
authors.initials: T
authors.lastname: Shimada
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Koumoto
authors.forename: Lixin
authors.initials: L
authors.lastname: Li
authors.forename: Misako
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Maki
authors.initials: M
authors.lastname: Kondo
authors.forename: Mikio
authors.initials: M
authors.lastname: Nishimura
authors.forename: Ikuko
authors.initials: I
authors.lastname: Hara-Nishimura
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D030821:Plants, Genetically Modified; D021381:Protein Transport; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C515611:Mag1 protein, Arabidopsis; D033921:Vesicular Transport Proteins