Publications (3)16.92 Total impact
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Article: Complex assembly and metabolic profiling of Arabidopsis thaliana plants overexpressing vitamin B₆ biosynthesis proteins.
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ABSTRACT: In plants, vitamin B₆ biosynthesis requires the activity of PDX1 and PDX2 proteins. Arabidopsis thaliana encodes for three PDX1 proteins, named PDX1.1, 1.2, and 1.3, but only one PDX2. Here, we show in planta complex assembly of PDX proteins, based on split-YFP and FPLC assays, and can demonstrate their presence in higher complexes of around 750 kDa. Metabolic profiling of plants ectopically expressing the different PDX proteins indicates a negative influence of PDX1.2 on vitamin B₆ biosynthesis and a correlation between aberrant vitamin B6 content, PDX1 gene expression, and light sensitivity specifically for PDX1.3. These findings provide first insights into in planta vitamin B₆ synthase complex assembly and new information on how the different PDX proteins affect plant metabolism.Molecular plant 09/2010; 3(5):890-903. · 5.55 Impact Factor -
Article: Vitamin B6: a long known compound of surprising complexity.
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ABSTRACT: In recent years vitamin B6 has become a focus of research describing the compound's critical function in cellular metabolism and stress response. For many years the sole function of vitamin B6 was considered to be that of an enzymatic cofactor. However, recently it became clear that it is also a potent antioxidant that effectively quenches reactive oxygen species and is thus of high importance for cellular well-being. In view of the recent findings, the current review takes a look back and summarizes the discovery of vitamin B6 and the elucidation of its structure and biosynthetic pathways. It provides a detailed overview on vitamin B6 both as a cofactor and a protective compound. Besides these general characteristics of the vitamin, the review also outlines the current literature on vitamin B6 derivatives and elaborates on recent findings that provide new insights into transport and catabolism of the compound and on its impact on human health.Molecules 02/2009; 14(1):329-51. · 2.39 Impact Factor -
Article: Analysis of the Arabidopsis rsr4-1/pdx1-3 mutant reveals the critical function of the PDX1 protein family in metabolism, development, and vitamin B6 biosynthesis.
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ABSTRACT: Vitamin B6 represents a highly important group of compounds ubiquitous in all living organisms. It has been demonstrated to alleviate oxidative stress and in its phosphorylated form participates as a cofactor in >100 biochemical reactions. By means of a genetic approach, we have identified a novel mutant, rsr4-1 (for reduced sugar response), with aberrant root and leaf growth that requires supplementation of vitamin B6 for normal development. Cloning of the mutated gene revealed that rsr4-1 carries a point mutation in a member of the PDX1/SOR1/SNZ (for Pyridoxine biosynthesis protein 1/Singlet oxygen resistant 1/Snooze) family that leads to reduced vitamin B6 content. Consequently, metabolism is broadly altered, mainly affecting amino acid, raffinose, and shikimate contents and trichloroacetic acid cycle constituents. Yeast two-hybrid and pull-down analyses showed that Arabidopsis thaliana PDX1 proteins can form oligomers. Interestingly, the mutant form of PDX1 has severely reduced capability to oligomerize, potentially suggesting that oligomerization is important for function. In summary, our results demonstrate the critical function of the PDX1 protein family for metabolism, whole-plant development, and vitamin B6 biosynthesis in higher plants.The Plant Cell 08/2006; 18(7):1722-35. · 8.99 Impact Factor
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- The Plant Cell (1)
- Molecules (1)
- Molecular plant (1)
Institutions
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2006–2010
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Freie Universität Berlin
Berlin, Land Berlin, Germany
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2009
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Washington State University
- School of Biological Sciences
Pullman, WA, USA
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