Search results for "Phosphoserine phosphatase"
showing 7 items of 7 documents
Phosphoglycerate dehydrogenase genes differentially affect Arabidopsis metabolism and development.
2021
[EN] Unlike animals, plants possess diverse L-serine (Ser) biosynthetic pathways. One of them, the Phosphorylated Pathway of Serine Biosynthesis (PPSB) has been recently described as essential for embryo, pollen and root development, and required for ammonium and sulfur assimilation. The first and rate limiting step of PPSB is the reaction catalyzed by the enzyme phosphoglycerate dehydrogenase (PGDH). In Arabidopsis, the PGDH family consists of three genes, PGDH1, PGDH2 and PGDH3. PGDH1 is characterized as being the essential gene of the family. However, the biological significance of PGDH2 and PGDH3 remains unknown. In this manuscript, we have functionally characterized PGDH2 and PGDH3. Ph…
Reverse screening on indicaxanthin from Opuntia ficus-indica as natural chemoactive and chemopreventive agent
2018
Indicaxanthin is a bioactive and bioavailable betalain pigment extracted from Opuntia ficus indica fruits. Indicaxanthin has pharmacokinetic proprieties, rarely found in other phytochemicals, and it has been demonstrated that it provides a broad-spectrum of pharmaceutical activity, exerting anti-proliferative, anti-inflammatory, and neuromodulator effects. The discovery of the Indicaxanthin physiological targets plays an important role in understanding the biochemical mechanism. In this study, combined reverse pharmacophore mapping, reverse docking, and text-based database search identified Inositol Trisphosphate 3-Kinase (ITP3K-A), Glutamate carboxypeptidase II (GCPII), Leukotriene-A4 hydr…
Structural Analysis of Phosphoserine Aminotransferase (Isoform 1) From Arabidopsis thaliana– the Enzyme Involved in the Phosphorylated Pathway of Ser…
2018
Phosphoserine aminotransferase (PSAT) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that catalyzes the conversion of 3-phosphohydroxypyruvate (3-PHP) to 3-phosphoserine (PSer) in an L-glutamate (Glu)-linked reversible transamination reaction. This process proceeds through a bimolecular ping-pong mechanism and in plants takes place in plastids. It is a part of the phosphorylated pathway of serine biosynthesis, one of three routes recognized in plant organisms that yield serine. In this three-step biotransformation, 3-phosphoglycerate (3-PGA) delivered from plastidial glycolysis and Calvin cycle is oxidized by 3-PGA dehydrogenase. Then, 3-PHP is subjected to transamination with Glu to yi…
Lack of phosphoserine phosphatase activity alters pollen and tapetum development in Arabidopsis thaliana.
2015
Formation of mature pollen grain, an essential process for the reproduction of higher plants, is affected in lines that are deficient in the enzymes of the phosphorylated pathway of serine biosynthesis (PPSB). Mutants of phosphoserine phosphatase (PSP), the enzyme that catalyses the last step of PPSB, are embryo-lethal. When they are complemented with a construct carrying PSP1 cDNA under the control of the 35S promoter (psp1.1 35S:PSP1), which is poorly expressed in anther tissues, plants display a wild-type phenotype, but are male-sterile. The pollen from the psp1.1 35S:PSP1 lines are shrunken and unviable. Here we report the morphological alterations that appear in the psp1.1 35S:PSP1 lin…
Identification of the phosphoglycerate dehydrogenase isoform EDA9 as the essential gene for embryo and male gametophyte development in Arabidopsis
2013
[EN] Three different pathways of serine (Ser) biosynthesis have been described in plants: the Glycolate pathway, which is part of the Photorespiratory pathway, and 2 non-Photorespiratory pathways, the Glycerate and the Phosphorylated pathways. The Phosphorylated Pathway of Ser Biosynthesis (PPSB) has been known to exist since the 1950s, but its biological relevance was not revealed until quite recently when the last enzyme of the pathway, the Phosphoserine Phosphatase, was functionally characterized. In the associated study1, we characterized a family of genes coding for putatite phosphoglycerate dehydrogenases (PGDH, 3-PGDH, and EDA9), the first enzyme of the PPSB. A metabolomics study usi…
The essential role of the phosphorylated pathway of serine biosynthesis inArabidopsis
2013
[EN] In plants, 3 different pathways of serine biosynthesis have been described: the Glycolate pathway, which is associated with photorespiration, and 2 non-photorespiratory pathways, the Glycerate and the Phosphorylated pathways. The Phosphorylated Pathway of Serine Biosynthesis (PPSB) has been known since the 1950s, but has been studied relatively little, probably because it was considered of minor significance as compared with the Glycolate pathway. In the associated study1 , we described for the first time in plants the in vivo functional characterization of the PPSB, by targeting the phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Following a gain—and loss-of-function…
The phosphorylated pathway of serine biosynthesis is essential both for male gametophyte and embryo development and for root growth in Arabidopsis.
2013
This study characterizes the phosphorylated pathway of Ser biosynthesis (PPSB) in Arabidopsis thaliana by targeting phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Lack of PSP1 activity delayed embryo development, leading to aborted embryos that could be classified as early curled cotyledons. The embryo-lethal phenotype of psp1 mutants could be complemented with PSP1 cDNA under the control of Pro35S (Pro35S:PSP1). However, this construct, which was poorly expressed in the anther tapetum, did not complement mutant fertility. Microspore development in psp1.1/psp1.1 Pro35S:PSP1 arrested at the polarized stage. The tapetum from these lines displayed delayed and irregular devel…