Linked Life Data

12419184

Source:http://linkedlifedata.com/resource/pubmed/id/12419184

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2002-11-6
pubmed:abstractText
The biosynthesis of plant cell wall polysaccharides requires the concerted action of nucleotide sugar interconversion enzymes, nucleotide sugar transporters, and glycosyl transferases. How cell wall synthesis in planta is regulated, however, remains unclear. The root epidermal bulger 1 (reb1) mutant in Arabidopsis thaliana is partially deficient in cell wall arabinogalactan-protein (AGP), indicating a role for REB1 in AGP biosynthesis. We show that REB1 is allelic to ROOT HAIR DEFICIENT 1 (RHD1), one of five ubiquitously expressed genes that encode isoforms of UDP-D-glucose 4-epimerase (UGE), an enzyme that acts in the formation of UDP-D-galactose (UDP-D-Gal). The RHD1 isoform is specifically required for the galactosylation of xyloglucan (XG) and type II arabinogalactan (AGII) but is not involved either in D-galactose detoxification or in galactolipid biosynthesis. Epidermal cell walls in the root expansion zone lack arabinosylated (1-->6)-beta-D-galactan and galactosylated XG. In cortical cells of rhd1, galactosylated XG is absent, but an arabinosylated (1-->6)-beta-D-galactan is present. We conclude that the flux of galactose from UDP-D-Gal into different downstream products is compartmentalized at the level of cytosolic UGE isoforms. This suggests that substrate channeling plays a role in the regulation of plant cell wall biosynthesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0960-9822
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1840-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Galactose biosynthesis in Arabidopsis: genetic evidence for substrate channeling from UDP-D-galactose into cell wall polymers.
pubmed:affiliation
Department of Cell and Developmental Biology, John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't