Faculty Opinions recommendation of Shortening of membrane lipid acyl chains compensates for phosphatidylcholine deficiency in choline-auxotroph yeast.

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.

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

Biochemical Society Transactions ◽

10.1042/bst0331146 ◽

2005 ◽

Vol 33 (5) ◽

pp. 1146-1149 ◽

Cited By ~ 3

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.

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Manipulating membrane lipid profiles to restore T-cell function in autoimmunity

Biochemical Society Transactions ◽

10.1042/bst20150111 ◽

2015 ◽

Vol 43 (4) ◽

pp. 745-751 ◽

Cited By ~ 6

Author(s):

Kirsty E. Waddington ◽

Elizabeth C. Jury

Keyword(s):

T Cell ◽

Lipid Rafts ◽

Lupus Erythematosus ◽

Cell Function ◽

Immune Cell ◽

Membrane Lipids ◽

Membrane Lipid ◽

Plasma Membrane Lipid ◽

Disease Systemic Lupus Erythematosus ◽

Acyl Chains

Plasma membrane lipid rafts are heterogeneous cholesterol and glycosphingolipid (GSL)-enriched microdomains, within which the tight packing of cholesterol with the saturated-acyl chains of GSLs creates a region of liquid-order relative to the surrounding disordered membrane. Thus lipid rafts govern the lateral mobility and interaction of membrane proteins and regulate a plethora of signal transduction events, including T-cell antigen receptor (TCR) signalling. The pathways regulating homoeostasis of membrane cholesterol and GSLs are tightly controlled and alteration of these metabolic processes coincides with immune cell dysfunction as is evident in atherosclerosis, cancer and autoimmunity. Indeed, membrane lipid composition is emerging as an important factor influencing the ability of cells to respond appropriately to microenvironmental stimuli. Consequently, there is increasing interest in targeting membrane lipids or their metabolic control as a novel therapeutic approach to modulate immune cell behaviour and our recent work demonstrates that this is a promising strategy in T-cells from patients with the autoimmune disease systemic lupus erythematosus (SLE).

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Acute Cycling Exercise Induces Changes in Red Blood Cell Deformability and Membrane Lipid Remodeling

International Journal of Molecular Sciences ◽

10.3390/ijms22020896 ◽

2021 ◽

Vol 22 (2) ◽

pp. 896

Author(s):

Travis Nemkov ◽

Sarah C. Skinner ◽

Elie Nader ◽

Davide Stefanoni ◽

Mélanie Robert ◽

...

Keyword(s):

Physical Exertion ◽

Blood Rheology ◽

Active Role ◽

Membrane Lipid ◽

Fatty Acyl ◽

Cell Deformability ◽

Cycling Test ◽

Rbc Membrane ◽

Acyl Chains ◽

Response To Exercise

Here we describe the effects of a controlled, 30 min, high-intensity cycling test on blood rheology and the metabolic profiles of red blood cells (RBCs) and plasma from well-trained males. RBCs demonstrated decreased deformability and trended toward increased generation of microparticles after the test. Meanwhile, metabolomics and lipidomics highlighted oxidative stress and activation of membrane lipid remodeling mechanisms in order to cope with altered properties of circulation resulting from physical exertion during the cycling test. Of note, intermediates from coenzyme A (CoA) synthesis for conjugation to fatty acyl chains, in parallel with reversible conversion of carnitine and acylcarnitines, emerged as metabolites that significantly correlate with RBC deformability and the generation of microparticles during exercise. Taken together, we propose that RBC membrane remodeling and repair plays an active role in the physiologic response to exercise by altering RBC properties.

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Shortening of membrane lipid acyl chains compensates for phosphatidylcholine deficiency in choline‐auxotroph yeast

The EMBO Journal ◽

10.15252/embj.2021107966 ◽

2021 ◽

Author(s):

Xue Bao ◽

Martijn C Koorengevel ◽

Marian J A Groot Koerkamp ◽

Amir Homavar ◽

Amrah Weijn ◽

...

Keyword(s):

Membrane Lipid ◽

Acyl Chains

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Heat acclimation in rats: modulation via lipid polyunsaturation

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00423.2001 ◽

2002 ◽

Vol 283 (2) ◽

pp. R389-R399 ◽

Cited By ~ 10

Author(s):

Hilary Shmeeda ◽

Pavel Kaspler ◽

Judith Shleyer ◽

Reuma Honen ◽

Michal Horowitz ◽

...

Keyword(s):

Heat Stress ◽

Salivary Glands ◽

Lipid Composition ◽

Heat Acclimation ◽

Membrane Lipid ◽

Membrane Lipid Composition ◽

Cholesterol Levels ◽

Acute Heat Stress ◽

Acyl Chains

Heat acclimation of rats has been shown to enhance endurance of rat hearts to ischemic insult and acute heat stress. Common protective features have been shown to be operative during both these stress-inducing conditions. To explore the role of membrane lipid composition in the adaptive response, we analyzed two major parameters that impact membrane dynamics and order, the nonesterified cholesterol levels and the acyl chain composition of phospholipids, in rat heart and salivary glands, both major thermoregulatory organs, in short- and long-term heat-acclimated rats. Before exposure to heat, control salivary gland tissue has a higher cholesterol-to-phospholipid mole ratio (0.32 ± 0.02) than heart (0.14 ± 0.01), and the acyl chains of its phospholipids are 50% more saturated. The remodeling strategies of the tissues after exposure to heat differed. Heart cholesterol levels increased after short-term heat acclimation (∼50%), whereas salivary gland cholesterol levels decreased in acute heat stress and long-term heat acclimation (∼32%). Remodeling of phospholipid acyl chains, particularly an increase in docosahexaenoic acid, was a protective strategy in both tissues (57% in heart and >100% in salivary glands). Modifying membrane lipid composition by treating rats with liposomes composed of egg phosphatidylcholine (PC) before exposure to heat resulted in a 38% increase in endurance to thermal stress. The density and affinity of muscarinic receptors of submaxillary salivary glands, involved in the acclimation response, were measured in control and PC liposome-treated rats, and then both groups were subjected to short-term heat acclimation. After PC treatment the well-established compensatory upregulation of the muscarinic receptors and concomitant decrease in their affinity was blunted. The substantial increase in the thermal endurance of heat-challenged intact rats after treatment with PC liposomes (600 vs. 200 min) suggests that membrane lipid composition plays a role in the ability of these tissues to respond to heat stress.

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Lipid and Temperature Dependence of Membrane-Bound ATPase Activity of Acholeplasma laidlawii

Canadian Journal of Biochemistry ◽

10.1139/o74-136 ◽

1974 ◽

Vol 52 (11) ◽

pp. 974-980 ◽

Cited By ~ 24

Author(s):

Jean-Cheui Hsung ◽

Leaf Huang ◽

Daniel J. Hoy ◽

Alfred Haug

Keyword(s):

Atpase Activity ◽

Anisotropy Parameter ◽

Membrane Lipid ◽

Paramagnetic Resonance ◽

Lipid Fluidity ◽

Acholeplasma Laidlawii ◽

Straight Line ◽

Acyl Chains ◽

Membrane Bound ◽

Membrane Lipid Fluidity

Arrhenius plots (15–45 °C) of the ATPase activity of Acholeplasma laidlawii membranes enriched with either arachidoyl or saturated short-chain groups exhibited a pronounced discontinuity in slope around 25–30 °C, absent in oleoyl-enriched membranes. The membrane lipid fluidity was measured with a stearic acid spin label. At the growth temperature (37 °C) the membrane lipid fluidity was identical for all three kinds of enriched membranes. For membranes enriched with saturated acyl chains, a plot of the electron paramagnetic resonance anisotropy parameter 2T11vs. the reciprocal of temperature showed a biphasic profile with a discontinuity in slope around 25–30 °C. For oleoyl-group enriched membranes this plot yields only a straight line between 15 and 50 °C. Thus, lipids do play a role in the functioning of the membrane-bound ATPase. This enzyme is probably localized in the more fluid regions of the membrane.

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Denaturing interaction between sickle hemoglobin and phosphatidylserine liposomes

Blood ◽

10.1182/blood.v83.1.242.bloodjournal831242 ◽

1994 ◽

Vol 83 (1) ◽

pp. 242-249 ◽

Cited By ~ 1

Author(s):

E Marva ◽

RP Hebbel

Keyword(s):

Order Rate Constant ◽

Membrane Lipid ◽

Bovine Brain ◽

Lipid Phase ◽

Sickle Hemoglobin ◽

Oxidation Rates ◽

Low Salt ◽

Acyl Chains ◽

Red Blood Cell Membranes ◽

Heme Destruction

It is hypothesized that abnormal interaction between sickle hemoglobin (HbS) and erythrocyte membrane lipid might promote deposition of denatured hemoglobin (hemichrome) on the membrane. We compared the interaction of HbS and normal HbA with large unilamellar phosphatidylserine (PS) liposomes under low salt/pH conditions. Admixture of oxyHb and dioleoyl-PS resulted in loss of absorbance at 412 nm, the apparent first order rate constant for which was .25 +/- 0.02 hour-1 for HbA and .85 +/- 0.18 hour-1 for HbS. This was ascribable largely to formation of metHb and hemichromes and was accompanied by some actual transfer of heme from hemoglobin to lipid phase. By comparison, admixture of oxyHb with liposomes made from bovine brain PS having unsaturated acyl chains promoted even faster absorbance loss if the starting liposomal material contained detectable peroxidation by-product. In such cases, actual heme destruction developed with accompanying liberation of free iron and promotion of lipidperoxidation. Fluorescence quenching experiments indicate that hemoglobin/lipid interaction is characterized by very rapid initial electrostatic interaction, followed by development of irreversible changes. Similar changes still occur under conditions of physiologic salt/pH, but they develop much more slowly. The 3.4-fold faster oxidation of HbS versus HbA on lipid observed here represents an additional augmentation of the disparity in oxidation rates for hemoglobins in solution (1.7-fold faster for HbS than for HbA) observed previously. The accelerated promotion of Hb denaturation resulting from lipid contact may help explain deposits of hemichrome on sickle red blood cell membranes, particularly because these cells are in double jeopardy by virtue of having both the mutant HbS and abnormal amounts of peroxidized membrane lipid.

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Denaturing interaction between sickle hemoglobin and phosphatidylserine liposomes

Blood ◽

10.1182/blood.v83.1.242.242 ◽

1994 ◽

Vol 83 (1) ◽

pp. 242-249 ◽

Cited By ~ 32

Author(s):

E Marva ◽

RP Hebbel

Keyword(s):

Order Rate Constant ◽

Membrane Lipid ◽

Bovine Brain ◽

Lipid Phase ◽

Sickle Hemoglobin ◽

Oxidation Rates ◽

Low Salt ◽

Acyl Chains ◽

Red Blood Cell Membranes ◽

Heme Destruction

Abstract It is hypothesized that abnormal interaction between sickle hemoglobin (HbS) and erythrocyte membrane lipid might promote deposition of denatured hemoglobin (hemichrome) on the membrane. We compared the interaction of HbS and normal HbA with large unilamellar phosphatidylserine (PS) liposomes under low salt/pH conditions. Admixture of oxyHb and dioleoyl-PS resulted in loss of absorbance at 412 nm, the apparent first order rate constant for which was .25 +/- 0.02 hour-1 for HbA and .85 +/- 0.18 hour-1 for HbS. This was ascribable largely to formation of metHb and hemichromes and was accompanied by some actual transfer of heme from hemoglobin to lipid phase. By comparison, admixture of oxyHb with liposomes made from bovine brain PS having unsaturated acyl chains promoted even faster absorbance loss if the starting liposomal material contained detectable peroxidation by-product. In such cases, actual heme destruction developed with accompanying liberation of free iron and promotion of lipidperoxidation. Fluorescence quenching experiments indicate that hemoglobin/lipid interaction is characterized by very rapid initial electrostatic interaction, followed by development of irreversible changes. Similar changes still occur under conditions of physiologic salt/pH, but they develop much more slowly. The 3.4-fold faster oxidation of HbS versus HbA on lipid observed here represents an additional augmentation of the disparity in oxidation rates for hemoglobins in solution (1.7-fold faster for HbS than for HbA) observed previously. The accelerated promotion of Hb denaturation resulting from lipid contact may help explain deposits of hemichrome on sickle red blood cell membranes, particularly because these cells are in double jeopardy by virtue of having both the mutant HbS and abnormal amounts of peroxidized membrane lipid.

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