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111.
Oxidative pentose phosphate pathway-dependent sugar sensing as a mechanism for regulation of root ion transporters by photosynthesis 总被引:5,自引:0,他引:5
Root ion transport systems are regulated by light and/or sugars, but the signaling mechanisms are unknown. We showed previously that induction of the NRT2.1 NO(3)(-) transporter gene by sugars was dependent on carbon metabolism downstream hexokinase (HXK) in glycolysis. To gain further insights on this signaling pathway and to explore more systematically the mechanisms coordinating root nutrient uptake with photosynthesis, we studied the regulation of 19 light-/sugar-induced ion transporter genes. A combination of sugar, sugar analogs, light, and CO(2) treatments provided evidence that these genes are not regulated by a common mechanism and unraveled at least four different signaling pathways involved: regulation by light per se, by HXK-dependent sugar sensing, and by sugar sensing upstream or downstream HXK, respectively. More specific investigation of sugar-sensing downstream HXK, using NRT2.1 and NRT1.1 NO(3)(-) transporter genes as models, highlighted a correlation between expression of these genes and the concentration of glucose-6-P in the roots. Furthermore, the phosphogluconate dehydrogenase inhibitor 6-aminonicotinamide almost completely prevented induction of NRT2.1 and NRT1.1 by sucrose, indicating that glucose-6-P metabolization within the oxidative pentose phosphate pathway is required for generating the sugar signal. Out of the 19 genes investigated, most of those belonging to the NO(3)(-), NH(4)(+), and SO(4)(2-) transporter families were regulated like NRT2.1 and NRT1.1. These data suggest that a yet-unidentified oxidative pentose phosphate pathway-dependent sugar-sensing pathway governs the regulation of root nitrogen and sulfur acquisition by the carbon status of the plant to coordinate the availability of these three elements for amino acid synthesis. 相似文献
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Carolyn K. Dong Vishal Patel Jimmy C. Yang Jeffrey D. Dvorin Manoj T. Duraisingh Jon Clardy Dyann F. Wirth 《Bioorganic & medicinal chemistry letters》2009,19(3):972-975
Plasmodium falciparum NDH2 (pfNDH2) is a non-proton pumping, rotenone-insensitive alternative enzyme to the multi-subunit NADH:ubiquinone oxidoreductases (Complex I) of many other eukaryotes. Recombinantly expressed pfNDH2 prefers coenzyme CoQ0 as an acceptor substrate, and can also use the artificial electron acceptors, menadione and dichlorophenol–indophenol (DCIP). Previously characterized NDH2 inhibitors, dibenziodolium chloride (DPI), diphenyliodonium chloride (IDP), and 1-hydroxy-2-dodecyl-4(1H)quinolone (HDQ) do not inhibit pfNDH2 activity. Here, we provide evidence that HDQ likely targets another P. falciparum mitochondrial enzyme, dihydroorotate dehydrogenase (pfDHOD), which is essential for de novo pyrimidine biosynthesis. 相似文献
116.
Background
Searching for proteins that contain similar substructures is an important task in structural biology. The exact solution of most formulations of this problem, including a recently published method based on tableaux, is too slow for practical use in scanning a large database. 相似文献117.
Kristina Nehlsen Roland Schucht Leonor da Gama-Norton Wolfgang Krömer Alexandra Baer Aziz Cayli Hansjörg Hauser Dagmar Wirth 《BMC biotechnology》2009,9(1):100-12
Background
Recombinant protein expression in mammalian cells is mostly achieved by stable integration of transgenes into the chromosomal DNA of established cell lines. The chromosomal surroundings have strong influences on the expression of transgenes. The exploitation of defined loci by targeting expression constructs with different regulatory elements is an approach to design high level expression systems. Further, this allows to evaluate the impact of chromosomal surroundings on distinct vector constructs. 相似文献118.
Hahnen E Eyüpoglu IY Brichta L Haastert K Tränkle C Siebzehnrübl FA Riessland M Hölker I Claus P Romstöck J Buslei R Wirth B Blümcke I 《Journal of neurochemistry》2006,98(1):193-202
Among a panel of histone deacetylase (HDAC) inhibitors investigated, suberoylanilide hydroxamic acid (SAHA) evolved as a potent and non-toxic candidate drug for the treatment of spinal muscular atrophy (SMA), an alpha-motoneurone disorder caused by insufficient survival motor neuron (SMN) protein levels. SAHA increased SMN levels at low micromolar concentrations in several neuroectodermal tissues, including rat hippocampal brain slices and motoneurone-rich cell fractions, and its therapeutic capacity was confirmed using a novel human brain slice culture assay. SAHA activated survival motor neuron gene 2 (SMN2), the target gene for SMA therapy, and inhibited HDACs at submicromolar doses, providing evidence that SAHA is more efficient than the HDAC inhibitor valproic acid, which is under clinical investigation for SMA treatment. In contrast to SAHA, the compounds m-Carboxycinnamic acid bis-Hydroxamide, suberoyl bishydroxamic acid and M344 displayed unfavourable toxicity profiles, whereas MS-275 failed to increase SMN levels. Clinical trials have revealed that SAHA, which is under investigation for cancer treatment, has a good oral bioavailability and is well tolerated, allowing in vivo concentrations shown to increase SMN levels to be achieved. Because SAHA crosses the blood-brain barrier, oral administration may allow deceleration of progressive alpha-motoneurone degeneration by epigenetic SMN2 gene activation. 相似文献
119.
Mavromatis K Sikorski J Pabst E Teshima H Lapidus A Lucas S Nolan M Glavina Del Rio T Cheng JF Bruce D Goodwin L Pitluck S Liolios K Ivanova N Mikhailova N Pati A Chen A Palaniappan K Land M Hauser L Chang YJ Jeffries CD Rohde M Spring S Göker M Wirth R Woyke T Bristow J Eisen JA Markowitz V Hugenholtz P Klenk HP Kyrpides NC 《Standards in genomic sciences》2010,3(2):117-125
Vulcanisaeta distributa Itoh et al. 2002 belongs to the family Thermoproteaceae in the phylum Crenarchaeota. The genus Vulcanisaeta is characterized by a global distribution in hot and acidic springs. This is the first genome sequence from a member of the genus Vulcanisaeta and seventh genome sequence in the family Thermoproteaceae. The 2,374,137 bp long genome with its 2,544 protein-coding and 49 RNA genes is a part of the Genomic Encyclopedia of Bacteriaand Archaea project. 相似文献
120.
Zilbauer M Jenke A Wenzel G Postberg J Heusch A Phillips AD Noble-Jamieson G Torrente F Salvestrini C Heuschkel R Wirth S 《PloS one》2010,5(10):e15389