title: The cell morphogenesis gene SPIRRIG in Arabidopsis encodes a WD/BEACH domain protein.
abstract: WD40/BEACH domain proteins have been implicated in membrane trafficking and membrane composition events in Dictyostelium and Drosophila. In this paper, we show that the Arabidopsis SPIRRIG (SPI) gene encodes a WD40/BEACH domain protein. The cellular analysis revealed fragmented vacuoles in root hairs similar to those found in the corresponding Dictyostelium mutants, suggesting a related cellular function. The phenotypic analysis revealed that spi mutants share all phenotypic aspects of mutants in the actin polymerization-regulating ARP2/3 pathway, including distorted trichomes, less lobing of epidermal pavement cells, disconnected epidermal cells on various organs, and shorter root hairs. This complete phenotypic overlap suggests that this WD40/BEACH domain protein and the actin-regulating ARP2/3 pathway are involved in similar growth processes.
authors.affiliation: University of Cologne, Botanical Institute, 50931 Cologne, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Saedler
authors.forename: Marc
authors.initials: M
authors.lastname: Jakoby
authors.forename: Birger
authors.initials: B
authors.lastname: Marin
authors.forename: Elena
authors.initials: E
authors.lastname: Galiana-Jaime
authors.forename: Martin
authors.initials: M
authors.lastname: Hülskamp
mesh_terms: D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D009154:Mutation; D010802:Phylogeny; D018517:Plant Roots / Q000166:cytology / Q000235:genetics; D014617:Vacuoles / Q000648:ultrastructure
chemical_list: D051376:Actin-Related Protein 2-3 Complex; D029681:Arabidopsis Proteins; D018744:DNA, Plant