scholarly journals Lipid Acyl Chain Remodeling in Yeast

2015 ◽  
Vol 8s1 ◽  
pp. LPI.S31780 ◽  
Author(s):  
Mike F. Renne ◽  
Xue Bao ◽  
Cedric H. De Smet ◽  
Anton I. P. M. De Kroon
Keyword(s):  
Intracellular Transport ◽  
De Novo ◽  
Acyl Chain ◽  
Model Organism ◽  
Lipid Synthesis ◽  
Membrane Lipid ◽  
Lipid Homeostasis ◽  
Synthetic Process ◽  
Acyl Chains ◽  
Phospholipid Acyl Chain

Membrane lipid homeostasis is maintained by de novo synthesis, intracellular transport, remodeling, and degradation of lipid molecules. Glycerophospholipids, the most abundant structural component of eukaryotic membranes, are subject to acyl chain remodeling, which is defined as the post-synthetic process in which one or both acyl chains are exchanged. Here, we review studies addressing acyl chain remodeling of membrane glycerophospholipids in Saccharomyces cerevisiae, a model organism that has been successfully used to investigate lipid synthesis and its regulation. Experimental evidence for the occurrence of phospholipid acyl chain exchange in cardiolipin, phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine is summarized, including methods and tools that have been used for detecting remodeling. Progress in the identification of the enzymes involved is reported, and putative functions of acyl chain remodeling in yeast are discussed.

scholarly journals The elongation of exogenous fatty acids and the control of phospholipid acyl chain length in Micrococcus cryophilus

1980 ◽  
Vol 188 (3) ◽  
pp. 585-592 ◽  
Author(s):  
S P Sandercock ◽  
N J Russell
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
De Novo ◽  
Acyl Chain ◽  
Psychrophilic Bacterium ◽  
Fatty Acid Elongation ◽  
Acyl Chain Length ◽  
Acyl Chains ◽  
Phospholipid Acyl Chain

The synthesis of fatty acids de novo from acetate and the elongation of exogenous satuated fatty acids (C12-C18) by the psychrophilic bacterium Micrococcus cryophilus (A.T.C.C. 15174) grown at 1 or 20 degrees C was investigated. M. cryophilus normally contains only C16 and C18 acyl chains in its phospholipids, and the C18/C16 ratio is altered by changes in growth temperature. The bacterium was shown to regulate strictly its phospholipid acyl chain length and to be capable of directly elongating myristate and palmitate, and possibly laurate, to a mixture of C16 and C18 acyl chains. Retroconversion of stearate into palmitate also occurred. Fatty acid elongation could be distinguished from fatty acid synthesis de novo by the greater sensitivity of fatty acid elongation to inhibition by NaAsO2 under conditions when the supply of ATP and reduced nicotinamide nucleotides was not limiting. It is suggested that phospholipid acyl chain length may be controlled by a membrane-bound elongase enzyme, which interconverts C16 and C18 fatty acids via a C14 intermediate; the activity of the enzyme could be regulated by membrane lipid fluidity.

scholarly journals The contributions of biosynthesis and acyl chain remodelling to the molecular species profile of phosphatidylcholine in yeast

2005 ◽  
Vol 33 (5) ◽  
pp. 1146-1149 ◽  
Author(s):  
H.A. Boumann ◽  
A.I.P.M. de Kroon
Keyword(s):  
Stable Isotope ◽  
Species Composition ◽  
Molecular Species ◽  
Acyl Chain ◽  
Membrane Lipid ◽  
Molecular Species Composition ◽  
Stable Isotope Labelling ◽  
Membrane Function ◽  
Isotope Labelling ◽  
Acyl Chains

Phosphatidylcholine (PC) is a very abundant membrane lipid in most eukaryotes, including yeast. The molecular species profile of PC, i.e. the ensemble of PC molecules with acyl chains differing in number of carbon atoms and double bonds, is important for membrane function. Pathways of PC synthesis and turnover maintain PC homoeostasis and determine the molecular species profile of PC. Studies addressing the processes involved in establishing the molecular species composition of PC in yeast using stable isotope labelling combined with detection by MS are reviewed.

15-Deoxy-Δ12,14-prostaglandin J2 and peroxisome proliferator-activated receptor γ (PPARγ) levels in term placental tissues from control and diabetic rats: modulatory effects of a PPARγ agonist on nitridergic and lipid placental metabolism

2005 ◽  
Vol 17 (4) ◽  
pp. 423 ◽  
Author(s):  
E. Capobianco ◽  
A. Jawerbaum ◽  
M. C. Romanini ◽  
V. White ◽  
C. Pustovrh ◽  
...  
Keyword(s):  
De Novo ◽  
Lipid Synthesis ◽  
Diabetic Rats ◽  
Lipid Homeostasis ◽  
Diabetic Rat ◽  
No Production ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Pparγ Agonist ◽  
Prostaglandin J2

15-Deoxy-Δ12,14-prostaglandin J2 (15dPGJ2) is a peroxisome proliferator-activated receptor γ (PPARγ) ligand that regulates lipid homeostasis and has anti-inflammatory properties in many cell types. We postulated that 15dPGJ2 may regulate lipid homeostasis and nitric oxide (NO) levels in term placental tissues and that alterations in these pathways may be involved in diabetes-induced placental derangements. In the present study, we observed that, in term placental tissues from streptozotocin-induced diabetic rats, 15dPGJ2 concentrations were decreased (83%) and immunostaining for nitrotyrosine, indicating peroxynitrite-induced damage, was increased. In the presence of 15dPGJ2, concentrations of nitrates/nitrites (an index of NO production) were diminished (40%) in both control and diabetic rats, an effect that seems to be both dependent on and independent of PPARγ activation. Exogenous 15dPGJ2 did not modify lipid mass, but decreased the incorporation of 14C-acetate into triacylglycerol (35%), cholesteryl ester (55%) and phospholipid (32%) in placenta from control rats, an effect that appears to be dependent on PPARγ activation. In contrast, the addition of 15dPGJ2 did not alter de novo lipid synthesis in diabetic rat placenta, which showed decreased levels of PPARγ. We conclude that 15dPGJ2 modulates placental lipid metabolism and NO production. The concentration and function of 15dPGJ2 and concentrations of PPARγ were altered in placentas from diabetic rats, anomalies probably involved in diabetes-induced placental dysfunction.

scholarly journals Lipid synthesis in human erythroid cells: the effect of sickling

Blood ◽  
1976 ◽  
Vol 47 (2) ◽  
pp. 189-195 ◽  
Author(s):  
TA Lane ◽  
SK Ballas ◽  
ER Burka
Keyword(s):  
Cell Membrane ◽  
Neutral Lipid ◽  
Sickle Cell Anemia ◽  
De Novo ◽  
Membrane Lipids ◽  
Membrane Damage ◽  
Lipid Synthesis ◽  
Membrane Lipid ◽  
Erythroid Cell ◽  
Cell Membrane Damage

Abstract Human reticulocytes are capable of synthesizing membrane lipids from 14C-glycerol de novo. In both sickle and nonsickle reticulocytes the majority of 14C-glycerol was incorporated into phospholipids, primarily phosphatidylserine and phosphatidylcholine. Incorporation into sphingomyelin was minimal. The most abundant neutral lipid synthesized was triglyceride. In the absence of sickling, the rate of lipid synthesis in sickle reticulocytes was similar to that of nonsickle reticulocytes. With the induction of sickling under anoxic conditions sickle reticulocytes showed a prompt increase in the rate of lipid synthesis to an average of 69% above control values, while nonsickle reticulocytes under similar conditions decreased the rate of lipid synthesis. An increase in the rate of membrane lipid synthesis is associated in the mammalian erythroid cell with cell membrane damage. The findings further confirm that lesions of the erythroid cell membrane in sickle cell anemia are secondary to the sickling process itself.

scholarly journals Phospholipid Remodeling in Physiology and Disease

2019 ◽  
Vol 81 (1) ◽  
pp. 165-188 ◽  
Author(s):  
Bo Wang ◽  
Peter Tontonoz
Keyword(s):  
Viral Infections ◽  
De Novo ◽  
Acyl Chain ◽  
Phospholipid Composition ◽  
Fatty Acyl ◽  
De Novo Lipogenesis ◽  
Lipid Absorption ◽  
Fatty Acyl Chain ◽  
Nonalcoholic Fatty Liver ◽  
Acyl Chains

Phospholipids are major constituents of biological membranes. The fatty acyl chain composition of phospholipids determines the biophysical properties of membranes and thereby affects their impact on biological processes. The composition of fatty acyl chains is also actively regulated through a deacylation and reacylation pathway called Lands’ cycle. Recent studies of mouse genetic models have demonstrated that lysophosphatidylcholine acyltransferases (LPCATs), which catalyze the incorporation of fatty acyl chains into the sn-2 site of phosphatidylcholine, play important roles in pathophysiology. Two LPCAT family members, LPCAT1 and LPCAT3, have been particularly well studied. LPCAT1 is crucial for proper lung function due to its role in pulmonary surfactant biosynthesis. LPCAT3 maintains systemic lipid homeostasis by regulating lipid absorption in intestine, lipoprotein secretion, and de novo lipogenesis in liver. Mounting evidence also suggests that changes in LPCAT activity may be potentially involved in pathological conditions, including nonalcoholic fatty liver disease, atherosclerosis, viral infections, and cancer. Pharmacological manipulation of LPCAT activity and membrane phospholipid composition may provide new therapeutic options for these conditions.

Triacylglycerol as a precursor in phospholipid biosynthesis in cultured neuroblastoma cells: studies with labeled glucose, fatty acid, and triacylglycerol

1985 ◽  
Vol 63 (9) ◽  
pp. 919-926 ◽  
Author(s):  
H. W. Cook ◽  
M. W. Spence
Keyword(s):  
Fatty Acid ◽  
Time Course ◽  
De Novo ◽  
Acyl Chain ◽  
Neuroblastoma Cells ◽  
Fatty Acyl ◽  
Phospholipid Biosynthesis ◽  
Glycerol Moiety ◽  
Acyl Chains ◽  
Subsequent Incorporation

Neuroblastoma cells rapidly incorporate exogenous fatty acids into cellular triacylglycerol and relationships between triacylglycerol and phospholipid biosynthesis have been indicated by the relative time course of labeling of these lipids. To evaluate this further, neuroblastoma cells were labeled using potential precursors of phospholipid including radiolabeled triacyglycerol, glycerol, glucose, and fatty acid. With [2-3H]glycerol or a mixture of [2-3H]glycerol trioleate and glycerol tri[1-14C]oleate, phospholipids were labeled at very low levels (< 0.1 and < 0.5%, respectively). With [6-3H]glucose, labeling of lipids (0.5–3.5%) was greatest in medium containing 19 mM fructose, whereas labeling with [1-14C]18:2(n-6) was similar in media containing either 19 mM fructose or 25 mM glucose. Labeling of the glycerol moiety of triacylglycerol with [6-3H]glucose increased with 40–200 μM 18:2(n-6) present and occurred predominantly in 2 h. Some [6-3H]glucose label was in fatty acyl chains (chiefly 16:0) of triacylglycerol by 16 h, but was unaffected by exogenous 18:2(n-6). Triacylglycerol was the only lipid to increase in mass (threefold with 200 μM 18:2(n-6)). During the chase of cells pulsed with [6-3H]glucose, label in triacylglycerol declined within 0.5 h, whereas in phospholipid it increased transiently up to 2 h and then declined. Changes were inversely proportional to 18:2(n-6) levels in the chase medium and labeled acyl chains moved in parallel with the glycerol moiety. Thus, a major portion of acyl chain transfer from triacylglycerol was accompanied by glycerol. Triacylglycerol appears to serve as an expandable intracellular reservoir during an influx of acyl chains and subsequent incorporation of those acyl chains into phospholipid seems to involve some de novo phospholipid synthesis. As phospholipid mass does not change appreciably, such synthesis must be accompanied by equally rapid catabolism and turnover of membrane phospholipid.

Metabolism and control of lipid structure modification

1986 ◽  
Vol 64 (1) ◽  
pp. 66-69 ◽  
Author(s):  
Guy A. Thompson Jr.
Keyword(s):  
Lipid Composition ◽  
Physical State ◽  
Acyl Chain ◽  
Cellular Membrane ◽  
Membrane Lipid ◽  
Metabolizing Enzymes ◽  
Composition Characteristic ◽  
Compositional Changes ◽  
Phospholipid Acyl Chain ◽  
And Control

The lipid composition characteristic of a particular cellular membrane can become significantly altered, sometimes quite suddenly, when the cell is placed under environmental stress. In the majority of cases examined, the alterations seem to return the membrane's physical state towards that existing prior to imposition of the stress. The compositional changes are often diverse in their nature and also in their site of origin within the cell. Certain modifications, such as changes in the degree of phospholipid acyl chain unsaturation and in the reordering of fatty acid pairing on specific phospholipids, are now recognized as crucial first responses to stress, while others (e.g., fluctuations in relative proportions of different phospholipid classes and in the sterol:phospholipid ratio) develop more slowly and may represent secondary adjustments to the initial lipid changes. The factors directly responsible for modifying membrane lipid composition are generally unknown at the molecular level, but recent advances provide new clues favoring involvement, in some cases, of the ubiquitous mediator Ca2+. In other cases, the physical state of a membrane may directly modulate the activity of lipid-metabolizing enzymes embedded therein.

scholarly journals Lipids and Trehalose Actively Cooperate in Heat Stress Management of Schizosaccharomyces pombe

2021 ◽  
Vol 22 (24) ◽  
pp. 13272
Author(s):  
Mária Péter ◽  
Péter Gudmann ◽  
Zoltán Kóta ◽  
Zsolt Török ◽  
László Vígh ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Heat Stress ◽  
Schizosaccharomyces Pombe ◽  
De Novo ◽  
Acyl Chain ◽  
Membrane Lipid ◽  
Yeast Cells ◽  
Storage Lipids ◽  
Acyl Chain Length

Homeostatic maintenance of the physicochemical properties of cellular membranes is essential for life. In yeast, trehalose accumulation and lipid remodeling enable rapid adaptation to perturbations, but their crosstalk was not investigated. Here we report about the first in-depth, mass spectrometry-based lipidomic analysis on heat-stressed Schizosaccharomyces pombe mutants which are unable to synthesize (tps1Δ) or degrade (ntp1Δ) trehalose. Our experiments provide data about the role of trehalose as a membrane protectant in heat stress. We show that under conditions of trehalose deficiency, heat stress induced a comprehensive, distinctively high-degree lipidome reshaping in which structural, signaling and storage lipids acted in concert. In the absence of trehalose, membrane lipid remodeling was more pronounced and increased with increasing stress dose. It could be characterized by decreasing unsaturation and increasing acyl chain length, and required de novo synthesis of stearic acid (18:0) and very long-chain fatty acids to serve membrane rigidification. In addition, we detected enhanced and sustained signaling lipid generation to ensure transient cell cycle arrest as well as more intense triglyceride synthesis to accommodate membrane lipid-derived oleic acid (18:1) and newly synthesized but unused fatty acids. We also demonstrate that these changes were able to partially substitute for the missing role of trehalose and conferred measurable stress tolerance to fission yeast cells.

Control of membrane fluidity: the OLE pathway in focus

2017 ◽  
Vol 398 (2) ◽  
pp. 215-228 ◽  
Author(s):  
Stephanie Ballweg ◽  
Robert Ernst
Keyword(s):  
Membrane Fluidity ◽  
Unsaturated Fatty Acids ◽  
De Novo ◽  
Membrane Lipids ◽  
Current Knowledge ◽  
Acyl Chain ◽  
Membrane Integrity ◽  
Building Blocks ◽  
Membrane Lipid ◽  
Membrane Properties

Abstract The maintenance of a fluid lipid bilayer is key for membrane integrity and cell viability. We are only beginning to understand how eukaryotic cells sense and maintain the characteristic lipid compositions and bulk membrane properties of their organelles. One of the key factors determining membrane fluidity and phase behavior is the proportion of saturated and unsaturated acyl chains in membrane lipids. Saccharomyces cerevisiae is an ideal model organism to study the regulation of the lipid acyl chain composition via the OLE pathway. The OLE pathway comprises all steps involved in the regulated mobilization of the transcription factors Mga2 and Spt23 from the endoplasmic reticulum (ER), which then drive the expression of OLE1 in the nucleus. OLE1 encodes for the essential Δ9-fatty acid desaturase Ole1 and is crucial for de novo biosynthesis of unsaturated fatty acids (UFAs) that are used as lipid building blocks. This review summarizes our current knowledge of the OLE pathway, the best-characterized, eukaryotic sense-and-control system regulating membrane lipid saturation, and identifies open questions to indicate future directions.

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