TY  - JOUR
A1  - Klinghammer, Michaela
A1  - Tenhaken, Raimund
T1  - Genome-wide analysis of the UDP-glucose dehydrogenase gene family in Arabidopsis, a key enzyme for matrix polysaccharides in cell walls
T2  - The journal of experimental botany
N2  - Arabidopsis cell walls contain large amounts of pectins and hemicelluloses, which are predominantly synthesized via the common precursor UDP-glucuronic acid. The major enzyme for the formation of this nucleotide-sugar is UDP-glucose dehydrogenase, catalysing the irreversible oxidation of UDP-glucose into UDP-glucuronic acid. Four functional gene family members and one pseudogene are present in the Arabidopsis genome, and they show distinct tissue-specific expression patterns during plant development. The analyses of reporter gene lines indicate gene expression of UDP-glucose dehydrogenases in growing tissues. The biochemical characterization of the different isoforms shows equal affinities for the cofactor NAD+ (~40 µM) but variable affinities for the substrate UDP-glucose (120–335 µM) and different catalytic constants, suggesting a regulatory role for the different isoforms in carbon partitioning between cell wall formation and sucrose synthesis as the second major UDP-glucose-consuming pathway. UDP-glucose dehydrogenase is feedback inhibited by UDP-xylose. The relatively (compared with a soybean UDP-glucose dehydrogenase) low affinity of the enzymes for the substrate UDP-glucose is paralleled by the weak inhibition of the enzymes by UDP-xylose. The four Arabidopsis UDP-glucose dehydrogenase isoforms oxidize only UDP-glucose as a substrate. Nucleotide-sugars, which are converted by similar enzymes in bacteria, are not accepted as substrates for the Arabidopsis enzymes.
KW  - cell wall precursor
KW  - gene expression
KW  - hemicellulose
KW  - nucleotide-sugar
KW  - UDP-glucose dehydrogenase
Y1  - 2007
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/5851
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30-57949
SN  - 1460-2431
SN  - 0022-0957
N1  - (c) 2007 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
VL  - 58
IS  - 13
SP  - 3609
EP  - 3621
PB  - Oxford Univ. Press
CY  - Oxford
ER  -