AtVPS29, a putative component of a retromer complex, is required for the efficient sorting of seed storage proteins

• Published in: Plant and cell physiology Vol. 47; no. 9; pp. 1187 - 1194
• Main Authors: Shimada, T.(Kyoto Univ. (Japan)), Koumoto, Y, Li, L, Yamazaki, M, Kondo, M, Nishimura, M, Hara Nishimura, I
• Format: Journal Article
• Language: English
• Published: Japan Oxford Publishing Limited (England) 01.09.2006
• Subjects: Amino Acid Sequence; ARABIDOPSIS; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; CLASIFICACION DE PRODUCTOS; CLASSEMENT; Conserved Sequence; ENDOPLASMIC RETICULUM; GRADING; Molecular Sequence Data; Mutation; Phenotype; Plants, Genetically Modified; Protein Transport; PROTEINAS DE RESERVA; PROTEINE DE RESERVE; RETICULO ENDOPLASMATICO; RETICULUM ENDOPLASMIQUE; Saccharomyces cerevisiae; Seeds - genetics; Seeds - growth & development; Seeds - metabolism; STORAGE PROTEINS; VACUOLA; VACUOLE; VACUOLES; Vesicular Transport Proteins - genetics; Vesicular Transport Proteins - metabolism
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pcj103

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.