RRC ID 3100
著者 Noiriel A, Naponelli V, Bozzo GG, Gregory JF 3rd, Hanson AD.
タイトル Folate salvage in plants: pterin aldehyde reduction is mediated by multiple non-specific aldehyde reductases.
ジャーナル Plant J
Abstract Folates undergo oxidative cleavage in vivo, releasing a pterin aldehyde fragment that can be re-used in folate synthesis if the aldehyde group is reduced. High levels of NADPH-dependent reductase activity against pterin-6-aldehyde and its dihydro form were detected in Arabidopsis, pea and other plants; modeling predicted that the activity would maintain in vivo pterin aldehyde pools at extremely low levels (<0.2 pmol g(-1) FW). Subcellular fractionation showed that the pea leaf activity is mainly cytosolic, and anion exchange chromatography revealed multiple isoforms, all of which catalyzed reduction of other aldehydes. Arabidopsis seed activity likewise comprised various isoforms. An Arabidopsis gene (At1g10310) encoding a pterin aldehyde reductase was identified by searching the short-chain dehydrogenase/reductase family for proteins predicted to be NADPH-linked, and sharing conserved residues with reductases that mediate analogous reactions. The recombinant protein behaved as a dimer in size exclusion chromatography. In addition to pterin aldehydes, it catalyzed the reduction of diverse aromatic and aliphatic aldehydes: Vmax values varied <5-fold, but Km values ranged from 3.6 microm to 1.7 mm, those for pterin-6-aldehyde and dihydropterin-6-aldehyde being 36 and 56 microm, respectively. Activity with dihydropterin-6-aldehyde was unusually high at 0 degrees C. The At1g10310 transcript was most abundant in seeds, but, as expected for multiple isoforms, inactivating the At1g10310 gene caused only a minor change in seed pterin aldehyde reductase activity. We conclude that pterin aldehyde salvage in plants involves multiple, generalist NADPH-linked reductases, and that the At1g10310 enzyme is typical of these and hence suitable for use in engineering studies of folate turnover.
巻・号 51(3)
ページ 378-89
公開日 2007-8-1
DOI 10.1111/j.1365-313X.2007.03143.x
PII TPJ3143
PMID 17550420
MeSH Aldehyde Oxidoreductases / genetics Aldehyde Oxidoreductases / metabolism* Aldehyde Reductase / genetics Aldehyde Reductase / metabolism* Arabidopsis / genetics Arabidopsis Proteins / genetics Arabidopsis Proteins / metabolism* Folic Acid / metabolism* Gene Expression Gene Silencing Isoenzymes / metabolism Magnoliopsida / enzymology* Magnoliopsida / genetics NADP / metabolism Substrate Specificity
IF 6.141
引用数 18
WOS 分野 PLANT SCIENCES
リソース情報
シロイヌナズナ / 植物培養細胞・遺伝子 pst18173