Journal Article

<i>ZIP</i> Genes Encode Proteins Involved in Membrane Trafficking of the TGN–PVC/Vacuoles

Mitsuru Niihama, Noriko Takemoto, Yasuko Hashiguchi, Masao Tasaka and Miyo Terao Morita

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 50, issue 12, pages 2057-2068
Published in print December 2009 | ISSN: 0032-0781
Published online September 2009 | e-ISSN: 1471-9053 | DOI: http://dx.doi.org/10.1093/pcp/pcp137
ZIP Genes Encode Proteins Involved in Membrane Trafficking of the TGN–PVC/Vacuoles

More Like This

Show all results sharing these subjects:

  • Biochemistry
  • Molecular and Cell Biology
  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

The Arabidopsis zigzgag (zig) is a loss-of-function mutant of Qb-SNARE VTI11 which is involved in vesicle trafficking between the trans-Golgi network (TGN) and vacuoles. zig-1 exhibits abnormality in both shoot gravitropism and morphology. To elucidate the molecular network of the post-Golgi membrane trafficking in plant cells, we have isolated the suppressor mutants of zig. Here we report zig suppressor 2 (zip2) and zip4 that are recessive mutants and partially suppress abnormality in both gravitropism and morphology. ZIP2 encodes AtVPS41/AtVAM2 protein that is thought to be an Arabidopsis ortholog of yeast Vps41p/Vam2p, which is involved in protein sorting to vacuoles as a subunit of the tethering complex HOPS. Yeast Vps41p is also proposed to function in budding of adaptor protein (AP)-3-coated vesicles from the Golgi. The zip2 mutation is a missense mutation in a conserved amino acid of a putative clathrin heavy chain repeat (CHCR) domain. AtVPS41 is a single-copy gene in the Arabidopsis genome and the T-DNA insertion mutant appears to be lethal, whereas the zip2 single mutant showed no obvious phenotype. On the other hand, zip4 is a loss-of-function mutant of a putative ortholog of the yeast AP-3 μ subunit. In addition, loss-of-function mutants of other subunits of AP-3, ap-3β and ap-3δ, also exhibit a suppressive effect on the zig-1 phenotype. Although these genes are also single-copy genes in the genome, the loss-of-function mutants of AP-3 grow normally. Our results suggest that AtVPS41 and AP-3 play roles in the proper function of the post-Golgi trafficking network and support membrane trafficking to vacuoles.

Keywords: Arabidopsis; Genetics; Gravitropism; Membrane trafficking; Vacuole

Journal Article.  7694 words.  Illustrated.

Subjects: Biochemistry ; Molecular and Cell Biology ; Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.