Perception and transduction of low-temperature signals to induce desaturation of fatty acids

2000 ◽  
Vol 28 (6) ◽  
pp. 628-630 ◽  
Author(s):  
I. Suzuki ◽  
D. A. Los ◽  
N. Murata
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Low Temperature ◽  
Membrane Lipids ◽  
Response Regulator ◽  
Random Mutagenesis ◽  
Fatty Acid Desaturases ◽  
Histidine Kinases ◽  
Synechocystis Sp ◽  
Pcc 6803

When cells of the cyanobacterium Synechocystis sp. PCC 6803 are exposed to a low temperature, genes for fatty acid desaturases are expressed with resultant increases in the degree of unsaturation of fatty acids in membrane lipids. However, the sensor and transducers of low-temperature signals had not yet been identified. In order to identify these components we applied to the cyanobacterium Synechocystis sp. PCC 6803 the systematic disruption of all 43 putative genes for histidine kinases and random mutagenesis of the whole genome in conjunction with screening by the transcriptional activity of the promoter of the desB gene for the ω 3 desaturase. This allowed us to identify two histidine kinases and a response regulator as components of the perception and transduction of low-temperature signals for the expression of genes for fatty acid desaturases.

scholarly journals High-Light-Induced Stress Activates Lipid Deacylation at the Sn-2 Position in the Cyanobacterium Synechocystis sp. PCC 6803

2021 ◽  
Author(s):  
Kouji Kojima ◽  
Ui Matsumoto ◽  
Sumie Keta ◽  
Kenji Nakahigashi ◽  
Kazutaka Ikeda ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Palmitic Acid ◽  
Membrane Lipids ◽  
Acyl Carrier Protein ◽  
High Light ◽  
Growth Defect ◽  
Strong Light ◽  
Synechocystis Sp ◽  
Pcc 6803

Abstract Cyanobacterial mutants defective in acyl-acyl carrier protein synthetase (Aas) produce free fatty acids (FFAs) because the FFAs generated by deacylation of membrane lipids cannot be recycled. An engineered Aas-deficient mutant of Synechocystis sp. PCC 6803 grew normally under low-light (LL) conditions (50 µmol photons m-2 s-1) but was unable to sustain growth under high-light (HL) conditions (400 µmol photons m-2 s-1), revealing a crucial role of Aas in survival under the HL conditions. Several-times larger amounts of FFAs were produced by HL-exposed cultures than LL-grown cultures. Palmitic acid accounted for ~85% of total FFAs in HL-exposed cultures, while C18 fatty acids constituted ~80% of the FFAs in LL-grown cultures. Since C16 fatty acids are esterified to the sn-2 position of lipids in the Synechocystis species, it was deduced that HL irradiation activated deacylation of lipids at the sn-2 position. Heterologous expression of FarB, the FFA exporter protein of Neisseria lactamica, prevented intracellular FFA accumulation and rescued the growth defect of the mutant under HL, indicating that intracellular FFA was the cause of growth inhibition. FarB expression also decreased the per-cell yield of FFA under HL by 90% and decreased the proportion of palmitic acid to ~15% of total FFA. These results indicated that the HL-induced lipid deacylation is triggered not by strong light per se but by HL-induced damage to the cells. It was deduced that there is a positive feedback loop between HL-induced damage and lipid deacylation, which is lethal unless FFA accumulation is prevented by Aas.

scholarly journals Heat stress elicits remodeling in the anther lipidome of peanut

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zolian S. Zoong Lwe ◽  
Ruth Welti ◽  
Daniel Anco ◽  
Salman Naveed ◽  
Sachin Rustgi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Heat Stress ◽  
Fatty Acid ◽  
Membrane Lipids ◽  
Fatty Acid Desaturase ◽  
Susceptible Genotype ◽  
Unsaturated Lipid ◽  
Lipid Species ◽  
Lipid Unsaturation ◽  
Fatty Acid Amount

AbstractUnderstanding the changes in peanut (Arachis hypogaea L.) anther lipidome under heat stress (HT) will aid in understanding the mechanisms of heat tolerance. We profiled the anther lipidome of seven genotypes exposed to ambient temperature (AT) or HT during flowering. Under AT and HT, the lipidome was dominated by phosphatidylcholine (PC), phosphatidylethanolamine (PE), and triacylglycerol (TAG) species (> 50% of total lipids). Of 89 lipid analytes specified by total acyl carbons:total carbon–carbon double bonds, 36:6, 36:5, and 34:3 PC and 34:3 PE (all contain 18:3 fatty acid and decreased under HT) were the most important lipids that differentiated HT from AT. Heat stress caused decreases in unsaturation indices of membrane lipids, primarily due to decreases in highly-unsaturated lipid species that contained 18:3 fatty acids. In parallel, the expression of Fatty Acid Desaturase 3-2 (FAD3-2; converts 18:2 fatty acids to 18:3) decreased under HT for the heat-tolerant genotype SPT 06-07 but not for the susceptible genotype Bailey. Our results suggested that decreasing lipid unsaturation levels by lowering 18:3 fatty-acid amount through reducing FAD3 expression is likely an acclimation mechanism to heat stress in peanut. Thus, genotypes that are more efficient in doing so will be relatively more tolerant to HT.

Saccharomyces kluyveri FAD3 encodes an ω3 fatty acid desaturase

Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1983-1990 ◽  
Author(s):  
Takahiro Oura ◽  
Susumu Kajiwara
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Functional Characterization ◽  
Fatty Acid Desaturase ◽  
Fatty Acid Desaturases ◽  
Desaturase Gene ◽  
Saccharomyces Kluyveri ◽  
Fatty Acid Desaturase Gene

Fungi, like plants, are capable of producing the 18-carbon polyunsaturated fatty acids linoleic acid and α-linolenic acid. These fatty acids are synthesized by catalytic reactions of Δ12 and ω3 fatty acid desaturases. This paper describes the first cloning and functional characterization of a yeast ω3 fatty acid desaturase gene. The deduced protein encoded by the Saccharomyces kluyveri FAD3 gene (Sk-FAD3) consists of 419 amino acids, and shows 30–60 % identity with Δ12 fatty acid desaturases of several eukaryotic organisms and 29–31 % identity with ω3 fatty acid desaturases of animals and plants. During Sk-FAD3 expression in Saccharomyces cerevisiae, α-linolenic acid accumulated only when linoleic acid was added to the culture medium. The disruption of Sk-FAD3 led to the disappearance of α-linolenic acid in S. kluyveri. These findings suggest that Sk-FAD3 is the only ω3 fatty acid desaturase gene in this yeast. Furthermore, transcriptional expression of Sk-FAD3 appears to be regulated by low-temperature stress in a manner different from the other fatty acid desaturase genes in S. kluyveri.

Preliminary characterization of a photo-tolerant mutant of Synechocystis sp. PCC 6803 obtained by in vitro random mutagenesis of psbA2

Plant Science ◽  
1996 ◽  
Vol 115 (2) ◽  
pp. 261-266 ◽  
Author(s):  
Yoshihiro Narusaka ◽  
Akio Murakami ◽  
Mari Saeki ◽  
Hirokazu Kobayashi ◽  
Kimiyuki Satoh
Keyword(s):  
Random Mutagenesis ◽  
Preliminary Characterization ◽  
Tolerant Mutant ◽  
Synechocystis Sp ◽  
Pcc 6803

scholarly journals Phytohormones Regulate the Non-Redundant Response of ω-3 Fatty Acid Desaturases to Low Temperatures in Chorispora Bungeana

2021 ◽  
Author(s):  
Yulan Shi ◽  
Sizhong Yang ◽  
Xiule Yue ◽  
Zhixing Zhao ◽  
Lizhe An
Keyword(s):  
Fatty Acids ◽  
Abscisic Acid ◽  
Fatty Acid ◽  
Stress Response ◽  
Low Temperatures ◽  
Cultured Cells ◽  
Temperature Decrease ◽  
Fatty Acid Desaturases ◽  
Cold Environments ◽  
Chorispora Bungeana

Abstract To explore the contribution of ω-3 fatty acid desaturases (FADs) to cold stress response in a special cryophyte, Chorispora bungeana (C. bungeana), two plastidial ω-3 FAD genes (CbFAD7 and CbFAD8) were cloned and verified in a Arabidopsis fad7fad8 mutant, before being compared with the microsomal ω-3 FAD gene (CbFAD3) on expression profile. Though these genes were expressed in all tested tissues of C. bungeana, CbFAD7 and CbFAD8 have the highest expression in leaves, while CbFAD3 was mostly expressed in non-green tissues. Low temperatures (4, 0 and -4 ℃) resulted in significant increases in trienoic fatty acids (TAs, mainly C18:3), which were consistent with the non-redundant expression of CbFAD3 and CbFAD8 in suspension-cultured cells, and the coordination of CbFAD7 and CbFAD8 in leaves. Furthermore, the contribution of CbFAD8 increased as temperature decrease in the two tissues. Our data revealed that jasmonie acid and brassinosteroids participated in the cold-responsive expression of these genes in both tissues, and the pyhtohormone regulation in leaves was more complicated with the participation of abscisic acid and gibberellin. These results point to the hormone-regulated non-redundant contribution of ω-3 CbFADs to maintain appropriate level of TAs under low temperatures, which help C. bungeana survive in cold environments.

scholarly journals Nutritional ecology of essential fatty acids: an evolutionary perspective

2011 ◽  
Vol 59 (6) ◽  
pp. 369 ◽  
Author(s):  
A. J. Hulbert ◽  
Sarah K. Abbott
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Acid Composition ◽  
Membrane Lipids ◽  
Essential Fatty Acids ◽  
Dietary Fatty Acid ◽  
Omega 3 ◽  
Dietary Fatty Acid Composition

There are four types of fatty acids but only two types are essential nutritional requirements for many animals. These are the omega-6 polyunsaturated fatty acids (n-6 PUFA) and the omega-3 polyunsaturated fatty acids (n-3 PUFA) and because they cannot be converted to one another they are separate essential dietary requirements. They are only required in small amounts in the diet and their biological importance stems largely from their role as constituents of membrane lipids. They are synthesised by plants and, as a generalisation, green leaves are the source of n-3 PUFA while seeds are the source of n-6 PUFA in the food chain. While the fatty acid composition of storage fats (triglycerides) is strongly influenced by dietary fatty acid composition, this is not the case for membrane fats. The fatty acid composition of membrane lipids is relatively unresponsive to dietary fatty acid composition, although n-3 PUFA and n-6 PUFA can substitute for each in membrane lipids to some extent. Membrane fatty acid composition appears to be regulated and specific for different species. The role of essential fats in the diet of animals on (1) basal metabolic rate, (2) thermoregulation, (3) maximum longevity, and (4) exercise performance is discussed.

Elucidating butanol tolerance mediated by a response regulator Sll0039 in Synechocystis sp. PCC 6803 using a metabolomic approach

2015 ◽  
Vol 99 (4) ◽  
pp. 1845-1857 ◽  
Author(s):  
Xiangfeng Niu ◽  
Ye Zhu ◽  
Guangsheng Pei ◽  
Lina Wu ◽  
Lei Chen ◽  
...  
Keyword(s):  
Response Regulator ◽  
Butanol Tolerance ◽  
Metabolomic Approach ◽  
Synechocystis Sp ◽  
Pcc 6803
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