Disease relevance of DXR

• A proof of the enzymatic function of this protein was obtained by complementation of an Escherichia coli mutant defective in DXR activity [1].

High impact information on DXR

• Measurement of additional selected isoprenoid genes revealed that phytoene synthase (carotenoid pathway) displays similar fluctuations, whereas 1-deoxy-d-xylulose 5-phosphate reductoisomerase, possibly the first committed enzyme of the 1-deoxy-d-xylulose 5-phosphate pathway, only shows light regulation [2].
• The addition of 3% sucrose in the media slightly increased levels of DXS, DXR, IspD, IspE, and IspF mRNA in the dark [3].
• We demonstrate that Arabidopsis DXR is targeted to plastids and localizes into chloroplasts of leaf cells [1].
• Our results are consistent with the participation of the Arabidopsis DXR gene in the control of the 2-C-methyl-D-erythritol 4-phosphate pathway [1].
• The presence of the proline-rich region in the mature Arabidopsis DXR was confirmed by detection with a specific antibody [1].

Biological context of DXR

• The down-regulation of DXR resulted in variegation, reduced pigmentation and defects in chloroplast development, whereas DXR-overexpressing lines showed an increased accumulation of MEP- derived plastid isoprenoids such as chlorophylls, carotenoids, and taxadiene in transgenic plants engineered to produce this non-native isoprenoid [4].

Associations of DXR with chemical compounds

• The antibiotic fosmidomycin specifically inhibits this DXR enzyme activity [5].
• In this work, we have generated transgenic Arabidopsis thaliana plants with altered DXS and DXR enzyme levels, as estimated from their resistance to clomazone and fosmidomycin, respectively [4].
• These observations suggest that both AtMECT and DXR are important in the synthesis of isopentenyl diphosphate and dimethylallyl diphosphate and that ent-kaurene is mainly produced through the nonmevalonate pathway in the plastid [6].

References