open access

https://hdl.handle.net/2115/59480

Identification and Characterization of an Arabidopsis Mutant with Altered Localization of NIP5;1, a Plasma Membrane Boric Acid Channel, Reveals the Requirement for D-Galactose in Endomembrane Organization

英語

UDP-d-glucose-4-epimerase

2014-04

Oxford University Press

Plant and Cell Physiology

55(4)

704-714

Endomembrane organization is important for various aspects of cell physiology, including membrane protein trafficking. To explore the molecular mechanisms regulating the trafficking of plasma membrane-localized proteins in plants, we screened for Arabidopsis mutants with defective localization of green fluorescent protein (GFP)-nodulin 26-like intrinsic protein (NIP)5;1. Fluorescence imaging-based screening led to the isolation of a mutant which accumulated abnormal intracellular aggregates labeled by GFP-NIP5;1. The aggregates appeared in epidermal cells in the root elongation zone and included the trans-Golgi network/early endosomes. Rough mapping and whole-genome sequencing identified the mutant as an allele of UDP-glucose 4-epimerase 4 (uge4)/root hair defective 1 (rhd1) /root epidermal bulgar 1 (reb 1), which was originally defined as a cell wall mutant. The responsible gene encodes UDP-glucose 4-epimerase 4 (UGE4), which functions in the biosynthesis of d-galactose, especially for the synthesis of the cell wall polysaccharide xyloglucan and arabinogalactan proteins (AGPs). The endomembrane aggregates in the mutants were absent in the presence of d-galactose, indicative of a requirement for a d-galactose-containing component in endomembrane organization. Genetic and pharmacological analyses suggested that the aggregates were not caused by the disruption of cell wall polysaccharides or the cytoskeleton. Overall, our results suggest that UGE4 activity in d-galactose synthesis is required for the structure of cell wall polysaccharides and endomembrane organization.

学術雑誌論文

Accepted Manuscript

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Plant & Cell Physiology following peer review. The definitive publisher-authenticated version Plant Cell Physiol (2014) 55 (4): 704-714 is available online at: http://pcp.oxfordjournals.org/content/55/4/704.full?sid=8fdda2c4-6f13-4ee6-b47f-b4cb758342b3

0032-0781