scholarly journals FadD Is Required for Utilization of Endogenous Fatty Acids Released from Membrane Lipids

2011 ◽  
Vol 193 (22) ◽  
pp. 6295-6304 ◽  
Author(s):  
Ángel Pech-Canul ◽  
Joaquina Nogales ◽  
Alfonso Miranda-Molina ◽  
Laura Álvarez ◽  
Otto Geiger ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Stationary Phase ◽  
Free Fatty Acids ◽  
Sinorhizobium Meliloti ◽  
Membrane Lipids ◽  
Membrane Phospholipids ◽  
Content Type ◽  
Fatty Acid Transporter ◽  
In The Wild

FadD is an acyl coenzyme A (CoA) synthetase responsible for the activation of exogenous long-chain fatty acids (LCFA) into acyl-CoAs. Mutation offadDin the symbiotic nitrogen-fixing bacteriumSinorhizobium melilotipromotes swarming motility and leads to defects in nodulation of alfalfa plants. In this study, we found thatS. melilotifadDmutants accumulated a mixture of free fatty acids during the stationary phase of growth. The composition of the free fatty acid pool and the results obtained after specific labeling of esterified fatty acids with a Δ5-desaturase (Δ5-Des) were in agreement with membrane phospholipids being the origin of the released fatty acids.Escherichia colifadDmutants also accumulated free fatty acids released from membrane lipids in the stationary phase. This phenomenon did not occur in a mutant ofE. coliwith a deficient FadL fatty acid transporter, suggesting that the accumulation of fatty acids infadDmutants occurs inside the cell. Our results indicate that, besides the activation of exogenous LCFA, in bacteria FadD plays a major role in the activation of endogenous fatty acids released from membrane lipids. Furthermore, expression analysis performed withS. melilotirevealed that a functional FadD is required for the upregulation of genes involved in fatty acid degradation and suggested that in the wild-type strain, the fatty acids released from membrane lipids are degraded by β-oxidation in the stationary phase of growth.

scholarly journals Exogenous Polyunsaturated Fatty Acids Impact Membrane Remodeling and Affect Virulence Phenotypes among Pathogenic Vibrio Species

2017 ◽  
Vol 83 (22) ◽  
Author(s):  
Anna R. Moravec ◽  
Andrew W. Siv ◽  
Chelsea R. Hobby ◽  
Emily N. Lindsay ◽  
Layla V. Norbash ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Membrane Permeability ◽  
Stress Responses ◽  
Biofilm Formation ◽  
Membrane Lipids ◽  
Regulation Of Gene Expression ◽  
Exogenous Fatty Acid ◽  
Content Type

ABSTRACT The pathogenic Vibrio species (V. cholerae, V. parahaemolyticus, and V. vulnificus) represent a constant threat to human health, causing foodborne and skin wound infections as a result of ingestion of or exposure to contaminated water and seafood. Recent studies have highlighted Vibrio's ability to acquire fatty acids from environmental sources and assimilate them into cell membranes. The possession and conservation of such machinery provokes consideration of fatty acids as important factors in the pathogenic lifestyle of Vibrio species. The findings here link exogenous fatty acid exposure to changes in bacterial membrane phospholipid structure, permeability, phenotypes associated with virulence, and consequent stress responses that may impact survival and persistence of pathogenic Vibrio species. Polyunsaturated fatty acids (PUFAs) (ranging in carbon length and unsaturation) supplied in growth medium were assimilated into bacterial phospholipids, as determined by thin-layer chromatography and liquid chromatography-mass spectrometry. The incorporation of fatty acids variably affected membrane permeability, as judged by uptake of the hydrophobic compound crystal violet. For each species, certain fatty acids were identified as affecting resistance to antimicrobial peptide treatment. Significant fluctuations were observed with regard to both motility and biofilm formation following growth in the presence of individual PUFAs. Our results illustrate the important and complex roles of exogenous fatty acids in the membrane physiology and virulence of a bacterial genus that inhabits aquatic and host environments containing an abundance of diverse fatty acids. IMPORTANCE Bacterial responses to fatty acids include, but are not limited to, degradation for metabolic gain, modification of membrane lipids, alteration of protein function, and regulation of gene expression. Vibrio species exhibit significant diversity with regard to the machinery known to participate in the uptake and incorporation of fatty acids into their membranes. Both aquatic and host niches occupied by Vibrio are rife with various free fatty acids and fatty acid-containing lipids. The roles of fatty acids in the environmental survival and pathogenesis of bacteria have begun to emerge and are expected to expand significantly. The current study demonstrates the responsiveness of V. cholerae, V. parahaemolyticus, and V. vulnificus to exogenous PUFAs. In addition to phospholipid remodeling, PUFA assimilation impacts membrane permeability, motility, biofilm formation, and resistance to polymyxin B.

scholarly journals Acquisition of membrane lipids by differentiating glyoxysomes: role of lipid bodies.

1991 ◽  
Vol 115 (4) ◽  
pp. 995-1007 ◽  
Author(s):  
K D Chapman ◽  
R N Trelease
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Cotton Seed ◽  
Membrane Lipids ◽  
Nonpolar Lipid ◽  
Lipid Bodies ◽  
Membrane Phospholipids ◽  
Free System ◽  
Nonpolar Lipids

Glyoxysomes in cotyledons of cotton (Gossypium hirsutum, L.) seedlings enlarge dramatically within 48 h after seed imbibition (Kunce, C.M., R.N. Trelease, and D.C. Doman. 1984. Planta (Berl.). 161:156-164) to effect mobilization of stored cotton-seed oil. We discovered that the membranes of enlarging glyoxysomes at all stages examined contained a large percentage (36-62% by weight) of nonpolar lipid, nearly all of which were triacylglycerols (TAGs) and TAG metabolites. Free fatty acids comprised the largest percentage of these nonpolar lipids. Six uncommon (and as yet unidentified) fatty acids constituted the majority (51%) of both the free fatty acids and the fatty acids in TAGs of glyoxysome membranes; the same six uncommon fatty acids were less than 7% of the acyl constituents in TAGs extracted from cotton-seed storage lipid bodies. TAGs of lipid bodies primarily were composed of palmitic, oleic, and linoleic acids (together 70%). Together, these three major storage fatty acids were less than 10% of both the free fatty acids and fatty acids in TAGs of glyoxysome membranes. Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) constituted a major portion of glyoxysome membrane phospholipids (together 61% by weight). Pulse-chase radiolabeling experiments in vivo clearly demonstrated that 14C-PC and 14C-PE were synthesized from 14C-choline and 14C-ethanolamine, respectively, in ER of cotyledons, and then transported to mitochondria; however, these lipids were not transported to enlarging glyoxysomes. The lack of ER involvement in glyoxysome membrane phospholipid synthesis, and the similarities in lipid compositions between lipid bodies and membranes of glyoxysomes, led us to formulate and test a new hypothesis whereby lipid bodies serve as the dynamic source of nonpolar lipids and phospholipids for membrane expansion of enlarging glyoxysomes. In a cell-free system, 3H-triolein (TO) and 3H-PC were indeed transferred from lipid bodies to glyoxysomes. 3H-PC, but not 3H-TO, also was transferred to mitochondria in vitro. The amount of lipid transferred increased linearly with respect to time and amount of acceptor organelle protein, and transfer occurred only when lipid body membrane proteins were associated with the donor lipid bodies. 3H-TO was transferred to and incorporated into glyoxysome membranes, and then hydrolyzed to free fatty acids. 3H-PC was transferred to and incorporated into glyoxysome and mitochondria membranes without subsequent hydrolysis. Our data are inconsistent with the hypothesis that ER contributes membrane lipids to glyoxysomes during postgerminative seedling growth.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of transient ischemia on free fatty acids and phospholipids in the gerbil brain

1980 ◽  
Vol 53 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Shinichi Yoshida ◽  
Satoshi Inoh ◽  
Takao Asano ◽  
Keiji Sano ◽  
Masaru Kubota ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Saturated Fatty Acids ◽  
Hydrolytic Enzymes ◽  
Lipid Peroxides ◽  
Thiobarbituric Acid ◽  
Mitochondrial Respiratory Chain ◽  
Membrane Phospholipids ◽  
Content Type ◽  
Bilateral Carotid

✓ The effect of transient bilateral carotid occlusion on levels of free fatty acids, phospholipids, and lipid peroxides in the brain was studied in gerbils. During occlusion, both saturated and polyunsaturated free fatty acids increased strikingly to approximately 11-fold in total by 30 minutes. During recirculation, however, a selectively rapid decrement occurred in arachidonic acid, while saturated fatty acids gradually decreased to their basal levels in 180 minutes. The peroxide level, estimated by a thiobarbituric acid test, did not change during occlusion, but was elevated on reperfusion. Phosphatidylethanolamine content decreased throughout the periods examined. These results do not support a hypothesis that lipid peroxidation is initiated during ischemia by the lack of oxygen at the terminus of the mitochondrial respiratory chain. Instead, it is suggested that severe cerebral ischemia disintegrates membrane phospholipids, probably through activation of hydrolytic enzymes, and that overt peroxidative processes take place during reflow by means of restoration of oxygen supply. The peroxidative reactions may, indeed, cause additional damage during the postischemic phase.

Action of phospholipases A2 and C on free fatty acid release during complete ischemia in rat neocortex

1992 ◽  
Vol 76 (4) ◽  
pp. 648-651 ◽  
Author(s):  
Atsushi Umemura ◽  
Hideo Mabe ◽  
Hajime Nagai ◽  
Fumihiko sugino
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Phospholipase C ◽  
Phenylmethylsulfonyl Fluoride ◽  
Content Type ◽  
Rat Neocortex ◽  
Fatty Acid Release ◽  
Acid Release

✓ The levels of brain free fatty acids rapidly increase after the onset of ischemia. The purpose of this study was to investigate the action of phospholipases A2 and C during complete ischemia based on the effects of a phospholipase C inhibitor (phenylmethylsulfonyl fluoride) and the N-methyl-D-aspartate antagonist MK-801 on the release of free fatty acids in rat neocortex. Complete brain ischemia was induced in rats with cardiac arrest by intracardiac injection of KC1. Free fatty acid levels in the neocortex were measured 0, 2, 4, and 8 minutes after cardiac arrest. Phenylmethylsulfonyl fluoride inhibited the release of free fatty acids primarily from phosphatidylinositol during the first 2 minutes of ischemia and from phosphatidylcholine and phosphatidylethanolamine at 4 to 8 minutes of ischemia. Conversely, MK-801 inhibited free fatty acid release mainly from phosphatidylcholine and phosphatidylethanolamine at 2 to 4 minutes of ischemia. These results indicate that the release of free fatty acids during the first 2 minutes of ischemia can be attributed mostly to the action of phospholipase C, and that the activation of phospholipase C further influences the activation of phospholipase A2 in the subsequent course, while phospholipase A2 predominantly acts after 2 minutes of ischemia.

scholarly journals Membrane Stresses Induced by Overproduction of Free Fatty Acids in Escherichia coli

2011 ◽  
Vol 77 (22) ◽  
pp. 8114-8128 ◽  
Author(s):  
Rebecca M. Lennen ◽  
Max A. Kruziki ◽  
Kritika Kumar ◽  
Robert A. Zinkel ◽  
Kristin E. Burnum ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Unsaturated Fatty Acid ◽  
High Energy ◽  
High Energy Density ◽  
Content Type ◽  
E Coli ◽  
Expression Of Genes

ABSTRACTMicrobially produced fatty acids are potential precursors to high-energy-density biofuels, including alkanes and alkyl ethyl esters, by either catalytic conversion of free fatty acids (FFAs) or enzymatic conversion of acyl-acyl carrier protein or acyl-coenzyme A intermediates. Metabolic engineering efforts aimed at overproducing FFAs inEscherichia colihave achieved less than 30% of the maximum theoretical yield on the supplied carbon source. In this work, the viability, morphology, transcript levels, and protein levels of a strain ofE. colithat overproduces medium-chain-length FFAs was compared to an engineered control strain. By early stationary phase, an 85% reduction in viable cell counts and exacerbated loss of inner membrane integrity were observed in the FFA-overproducing strain. These effects were enhanced in strains endogenously producing FFAs compared to strains exposed to exogenously fed FFAs. Under two sets of cultivation conditions, long-chain unsaturated fatty acid content greatly increased, and the expression of genes and proteins required for unsaturated fatty acid biosynthesis were significantly decreased. Membrane stresses were further implicated by increased expression of genes and proteins of the phage shock response, the MarA/Rob/SoxS regulon, and thenuoandcyooperons of aerobic respiration. Gene deletion studies confirmed the importance of the phage shock proteins and Rob for maintaining cell viability; however, little to no change in FFA titer was observed after 24 h of cultivation. The results of this study serve as a baseline for future targeted attempts to improve FFA yields and titers inE. coli.

scholarly journals Cyclopropanation of Membrane Unsaturated Fatty Acids Is Not Essential to the Acid Stress Response of Lactococcus lactis subsp. cremoris

2011 ◽  
Vol 77 (10) ◽  
pp. 3327-3334 ◽  
Author(s):  
Thi Mai Huong To ◽  
Cosette Grandvalet ◽  
Raphaëlle Tourdot-Maréchal
Keyword(s):  
Fatty Acids ◽  
Stationary Phase ◽  
Lactococcus Lactis ◽  
Unsaturated Fatty Acids ◽  
Acid Stress ◽  
Acid Tolerance ◽  
Phase Cell ◽  
Wild Type ◽  
Membrane Phospholipids ◽  
Content Type

ABSTRACTCyclopropane fatty acids (CFAs) are synthetizedin situby the transfer of a methylene group fromS-adenosyl-l-methionine to a double bond of unsaturated fatty acid chains of membrane phospholipids. This conversion, catalyzed by the Cfa synthase enzyme, occurs in many bacteria and is recognized to play a key role in the adaptation of bacteria in response to a drastic perturbation of the environment. The role of CFAs in the acid tolerance response was investigated in the lactic acid bacteriumLactococcus lactisMG1363. A mutant of thecfagene was constructed by allelic exchange. Thecfagene encoding the Cfa synthase was cloned and introduced into the mutant to obtain the complemented strain for homologous system studies. Data obtained by gas chromatography (GC) and GC-mass spectrometry (GC-MS) validated that the mutant could not produce CFA. The CFA levels in both the wild-type and complemented strains increased upon their entry to stationary phase, especially with acid-adapted cells or, more surprisingly, with ethanol-adapted cells. The results obtained by performing quantitative reverse transcription-PCR (qRT-PCR) experiments showed that transcription of thecfagene was highly induced by acidity (by 10-fold with cells grown at pH 5.0) and by ethanol (by 9-fold with cells grown with 6% ethanol) in comparison with that in stationary phase. Cell viability experiments were performed after an acidic shock on the mutant strain, the wild-type strain, and the complemented strain, as a control. The higher viability level of the acid-adapted cells of the three strains after 3 h of shock proved that the cyclopropanation of unsaturated fatty acids is not essential forL. lactissubsp.cremorissurvival under acidic conditions. Moreover, fluorescence anisotropy data showed that CFA itself could not maintain the membrane fluidity level, particularly with ethanol-grown cells.

scholarly journals Role of Sinorhizobium meliloti and Escherichia coli Long-Chain Acyl-CoA Synthetase FadD in Long-Term Survival

2020 ◽  
Vol 8 (4) ◽  
pp. 470
Author(s):  
Ángel de la Cruz Pech-Canul ◽  
Geovanny Rivera-Hernández ◽  
Joaquina Nogales ◽  
Otto Geiger ◽  
María J. Soto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Carbon Source ◽  
Stationary Phase ◽  
Sole Carbon Source ◽  
Sinorhizobium Meliloti ◽  
Membrane Lipids ◽  
Term Survival ◽  
Long Chain

FadD is an acyl-coenzyme A (CoA) synthetase specific for long-chain fatty acids (LCFA). Strains mutated in fadD cannot produce acyl-CoA and thus cannot grow on exogenous LCFA as the sole carbon source. Mutants in the fadD (smc02162) of Sinorhizobium meliloti are unable to grow on oleate as the sole carbon source and present an increased surface motility and accumulation of free fatty acids at the entry of the stationary phase of growth. In this study, we found that constitutive expression of the closest FadD homologues of S. meliloti, encoded by sma0150 and smb20650, could not revert any of the mutant phenotypes. In contrast, the expression of Escherichia coli fadD could restore the same functions as S. meliloti fadD. Previously, we demonstrated that FadD is required for the degradation of endogenous fatty acids released from membrane lipids. Here, we show that absence of a functional fadD provokes a significant loss of viability in cultures of E. coli and of S. meliloti in the stationary phase, demonstrating a crucial role of fatty acid degradation in survival capacity.

Quantitative Effects of Unsaturated Fatty Acids in Microbial Mutants. IV. Lipid Composition of Saccharomyces cerevisiae When Growth is Limited by Unsaturated Fatty Acid Supply

1975 ◽  
Vol 53 (12) ◽  
pp. 1262-1277 ◽  
Author(s):  
Bruce J. Holub ◽  
William E. M. Lands
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Stationary Phase ◽  
Unsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Total Phospholipid ◽  
Phospholipid Content ◽  
Membrane Phospholipids ◽  
Mole Percentage

The Saccharomyces cerevisiae mutant KD46 (ole 2), which is unable to synthesize unsaturated fatty acids, was grown on limiting amounts of different added unsaturated fatty acids. The acyl chain composition of the cellular lipid classes was determined in these cultures at different stages of growth. During growth on added oleic acid, there was no marked change in the mole percentage of phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, or phosphatidylserine among the total phospholipids.Cells grown on palmitoleic, oleic, or linoleic acid showed a steady decrease in their total phospholipid levels per cell concomitant with a decrease in growth rate approaching minimal levels at stationary phase. Furthermore, the mole percentage of the supplemented unsaturated fatty acid in the cellular phospholipids also decreased during growth and attained minimal values when growth ceased.At stationary phase the total phospholipid content per cell was similar for cells grown on a wide range of fatty acids or mixtures thereof, whereas the composition of the fatty acids in the cellular phospholipids were strikingly different. The differences in efficiencies for supporting growth of most of the unsaturated fatty acids tested did not seem due to the extent of their incorporation into cellular phospholipids, but rather to differences in the ability of the derived membrane phospholipids to support cellular functions.Palmitoleate, oleate, linoleate, linolenate, arachidonate, eicosapentaenoate, and docosahexaenoate all appeared to contribute to the functionality of cellular membranes in an additive linear manner. Thus, the contribution of these acids to cellular growth can be characterized by a functionality factor that seems independent of the mixtures of acids supporting growth. Use of the functionality concept allows the cumulative influence of many different acids to be summarized quantitatively by a single number rather than resorting to qualitative descriptions of the degree of unsaturation or 'fitness' of the membrane phospholipids.

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.

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