Over-expression of Rate-Limiting Enzymes to Improve Alkaloid Productivity

2010 ◽  
pp. 95-109 ◽  
Author(s):  
Tomoya Takemura ◽  
Yit-lai Chow ◽  
Takehiko Todokoro ◽  
Takuya Okamoto ◽  
Fumihiko Sato
Keyword(s):  
Over Expression ◽  
Rate Limiting

scholarly journals Over-expression of the brassinosteroid gene TaDWF4 increases wheat productivity under low and sufficient nitrogen through enhanced carbon assimilation

2021 ◽  
Author(s):  
Matthew John Milner ◽  
Stéphanie M. Swarbreck ◽  
Melanie Craze ◽  
Sarah Bowden ◽  
Howard Griffiths ◽  
...  
Keyword(s):  
Crop Yields ◽  
Agronomic Traits ◽  
Carbon Assimilation ◽  
Fold Increase ◽  
Operating Efficiency ◽  
Over Expression ◽  
Rate Limiting Step ◽  
Marginal Soils ◽  
Use Efficiency ◽  
Rate Limiting

There is a strong pressure to reduce nitrogen (N) fertiliser inputs while maintaining or increasing current cereal crop yields. Brassinosteroids, (BR), are a group of phytohormones essential for plant growth and development, that have been demonstrated to regulate several agronomic traits. DWF4 encodes a cytochrome P450 that catalyses a rate-limiting step in BR synthesis. We show that overexpression of the dominant shoot expressed homoeologue TaDWF4-B in wheat can increase plant productivity by up to 105% under a range of N levels on marginal soils, resulting in increased N use efficiency (NUE). We show that a two to four-fold increase in TaDWF4 transcript levels enhances the responsiveness of genes regulated by N. The productivity increases seen were primarily due to the maintenance of photosystem II operating efficiency and carbon assimilation in plants when grown under limiting N conditions and not an overall increase in photosynthesis capacity. The increased biomass production and yield per plant in TaDWF4 OE lines could be linked to modified carbon partitioning and changes in expression pattern of the growth regulator Target Of Rapamycin, offering a route towards breeding for sustained yield and lower N inputs.

scholarly journals Palmitic acid causes increased dihydroceramide levels when desaturase expression is directly silenced or indirectly lowered by silencing AdipoR2

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Mario Ruiz ◽  
Marcus Henricsson ◽  
Jan Borén ◽  
Marc Pilon
Keyword(s):  
Palmitic Acid ◽  
Unsaturated Fatty Acids ◽  
Cultured Cells ◽  
De Novo ◽  
Strong Increase ◽  
Over Expression ◽  
C Elegans ◽  
Ceramide Synthesis ◽  
Positive Regulators ◽  
Rate Limiting

Abstract Background AdipoR1 and AdipoR2 (AdipoRs) are plasma membrane proteins often considered to act as adiponectin receptors with a ceramidase activity. Additionally, the AdipoRs and their yeast and C. elegans orthologs are emerging as membrane homeostasis regulators that counter membrane rigidification by promoting fatty acid desaturation and incorporation of unsaturated fatty acids into phospholipids, thus restoring fluidity. Methods Using cultured cells, the effects of AdipoR silencing or over-expression on the levels and composition of several sphingolipid classes were examined. Results AdipoR2 silencing in the presence of exogenous palmitic acid potently causes increased levels of dihydroceramides, a ceramide precursor in the de novo ceramide synthesis pathway. Conversely, AdipoR2 over-expression caused a depletion of dihydroceramides. Conclusions The results are consistent with AdipoR2 silencing leading to increased intracellular supply of palmitic acid that in turn leads to increased dihydroceramide synthesis via the rate-limiting serine palmitoyl transferase step. In agreement with this model, inhibiting the desaturase SCD or SREBF1/2 (positive regulators of SCD) also causes a strong increase in dihydroceramide levels.

The effect of over-expression of rate limiting enzymes on the yield of artemisinin in Artemisia annua

2015 ◽  
Vol 27 (2) ◽  
pp. 311-319 ◽  
Author(s):  
Pravej Alam ◽  
Kamaluddin ◽  
Mahmoud A. Sharaf-Eldin ◽  
Shereen F. Elkholy ◽  
Malik Zainul Abdin
Keyword(s):  
Artemisia Annua ◽  
Over Expression ◽  
Rate Limiting

1442: CXCL12 Over-Expression and Secretion by Aging Fibroblasts Stimulates Human Prostate Epithelial Proliferation in Vitro

2006 ◽  
Vol 175 (4S) ◽  
pp. 466-466
Author(s):  
Jill A. Macoska ◽  
Lesa Begley ◽  
Christine Monteleon ◽  
James W. MacDonald ◽  
Rajal B. Shah
Keyword(s):  
Human Prostate ◽  
Epithelial Proliferation ◽  
Over Expression ◽  
Proliferation In Vitro

Ornithine Decarboxylase Activity in Cultured Endothelial Cells Stimulated by Serum, Thrombin and Serotonin

1978 ◽  
Vol 39 (02) ◽  
pp. 496-503 ◽  
Author(s):  
P A D’Amore ◽  
H B Hechtman ◽  
D Shepro
Keyword(s):  
Endothelial Cells ◽  
Ornithine Decarboxylase ◽  
Decarboxylase Activity ◽  
Aortic Endothelial Cells ◽  
Ornithine Decarboxylase Activity ◽  
Rate Limiting Step ◽  
Bovine Aortic Endothelial Cells ◽  
Limiting Step ◽  
Rate Limiting ◽  
Serum Serotonin

SummaryOrnithine decarboxylase (ODC) activity, the rate-limiting step in the synthesis of polyamines, can be demonstrated in cultured, bovine, aortic endothelial cells (EC). Serum, serotonin and thrombin produce a rise in ODC activity. The serotonin-induced ODC activity is significantly blocked by imipramine (10-5 M) or Lilly 11 0140 (10-6M). Preincubation of EC with these blockers together almost completely depresses the 5-HT-stimulated ODC activity. These observations suggest a manner by which platelets may maintain EC structural and metabolic soundness.

Differences in the Interactions of Lupus Anticoagulant IgG with Human Prothrombin and Bovine Prothrombin

1995 ◽  
Vol 73 (04) ◽  
pp. 668-674 ◽  
Author(s):  
L Vijaya Mohan Rao ◽  
An D Hoang ◽  
Samuel I Rapaport
Keyword(s):  
Western Blot ◽  
Lupus Anticoagulant ◽  
Protein A ◽  
Phospholipid Complex ◽  
Experimental Conditions ◽  
Bovine Plasma ◽  
Activation System ◽  
Rate Limiting ◽  
Substantial Extent ◽  
Prothrombin Activation

SummaryLupus anticoagulant (LA) IgGs have been reported to inhibit more effectively and consistently the Xa/Va/phospholipid complex-catalyzed activation of human prothrombin than the Xa/Va/phospholipid complex-catalyzed activation of bovine prothrombin. This led us to carry out studies to determine whether the ability to inhibit the activation of prothrombin of LA IgGs, separated from the plasma of 15 patients by protein A affinity chromatography, could be related to the ability of the LA IgGs to bind to prothrombin under various experimental conditions. Of 14 LA IgG preparations tested all prolonged to a variable but substantial extent the dilute Russell’s viper venom time (dRVVT) of human plasma but only minimally prolonged the dRVVT of bovine plasma. In a purified prothrombin activation system with a rate limiting concentration of phospholipid, all 15 LA IgG preparations inhibited the activation of human prothrombin with the majority showing >50% of inhibition. In contrast, only one LA IgG markedly inhibited (>50%) the activation of bovine prothrombin and five others moderately inhibited (25-40%) the activation of bovine prothrombin. Nevertheless, the majority of LA IgG preparations bound to immobilized bovine prothrombin on a Western blot and also to immobilized bovine prothrombin on a microtiter well. In an ELISA in which phosphatidylserine (PS) was immobilized on microtiter wells, bovine prothrombin supported the binding of 10 of 15 LA IgG preparations to PS. However, the extent of binding was lower than that observed with human prothrombin. In experiments with 125I-human prothrombin or 125I-bovine prothrombin in a solution containing Ca2+, the addition of PS/PC vesicles enhanced the binding of both human and bovine prothrombin to some LA IgG preparations. The enhanced binding was particularly evident for bovine prothrombin. Although seemingly related for some preparations, the ability of a LA IgG to bind to bovine prothrombin, either in the presence or absence of PS, and the ability of that LA IgG to inhibit the activation of bovine prothrombin was not consistently related for all preparations.

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