scholarly journals Membrane Lipid Composition of the Moderately Thermophilic Ammonia-Oxidizing Archaeon “Candidatus Nitrosotenuis uzonensis” at Different Growth Temperatures

2019 ◽  
Vol 85 (20) ◽  
Author(s):  
Nicole J. Bale ◽  
Marton Palatinszky ◽  
W. Irene C. Rijpstra ◽  
Craig W. Herbold ◽  
Michael Wagner ◽  
...  
Keyword(s):  
Lipid Composition ◽  
Strong Influence ◽  
Thermal Spring ◽  
Membrane Lipid ◽  
Effect Of Temperature ◽  
Environmental Niche ◽  
Membrane Lipid Composition ◽  
Moderately Thermophilic ◽  
Wide Range ◽  
Membrane Spanning

ABSTRACT “Candidatus Nitrosotenuis uzonensis” is the only cultured moderately thermophilic member of the thaumarchaeotal order Nitrosopumilales (NP) that contains many mesophilic marine strains. We examined its membrane lipid composition at different growth temperatures (37°C, 46°C, and 50°C). Its lipids were all membrane-spanning glycerol dialkyl glycerol tetraethers (GDGTs), with 0 to 4 cyclopentane moieties. Crenarchaeol (cren), the characteristic thaumarchaeotal GDGT, and its isomer (crenʹ) were present in high abundance (30 to 70%). The GDGT polar headgroups were mono-, di-, and trihexoses and hexose/phosphohexose. The ratio of glycolipid to phospholipid GDGTs was highest in the cultures grown at 50°C. With increasing growth temperatures, the relative contributions of cren and crenʹ increased, while those of GDGT-0 to GDGT-4 (including isomers) decreased. TEX86 (tetraether index of tetraethers consisting of 86 carbons)-derived temperatures were much lower than the actual growth temperatures, further demonstrating that TEX86 does not accurately reflect the membrane lipid adaptation of thermophilic Thaumarchaeota. As the temperature increased, specific GDGTs changed relative to their isomers, possibly representing temperature adaption-induced changes in cyclopentane ring stereochemistry. Comparison of a wide range of thaumarchaeotal core lipid compositions revealed that the “Ca. Nitrosotenuis uzonensis” cultures clustered separately from other members of the NP order and the Nitrososphaerales (NS) order. While phylogeny generally seems to have a strong influence on GDGT distribution, our analysis of “Ca. Nitrosotenuis uzonensis” demonstrates that its terrestrial, higher-temperature niche has led to a lipid composition that clearly differentiates it from other NP members and that this difference is mostly driven by its high crenʹ content. IMPORTANCE For Thaumarchaeota, the ratio of their glycerol dialkyl glycerol tetraether (GDGT) lipids depends on growth temperature, a premise that forms the basis of the widely applied TEX86 paleotemperature proxy. A thorough understanding of which GDGTs are produced by which Thaumarchaeota and what the effect of temperature is on their GDGT composition is essential for constraining the TEX86 proxy. “Ca. Nitrosotenuis uzonensis” is a moderately thermophilic thaumarchaeote enriched from a thermal spring, setting it apart in its environmental niche from the other marine mesophilic members of its order. Indeed, we found that the GDGT composition of “Ca. Nitrosotenuis uzonensis” cultures was distinct from those of other members of its order and was more similar to those of other thermophilic, terrestrial Thaumarchaeota. This suggests that while phylogeny has a strong influence on GDGT distribution, the environmental niche that a thaumarchaeote inhabits also shapes its GDGT composition.

Effects of temperature on the structure and metabolism of cell membranes in fish

1984 ◽  
Vol 246 (4) ◽  
pp. R460-R470 ◽  
Author(s):  
J. R. Hazel
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Cold Exposure ◽  
Lipid Composition ◽  
Membrane Lipid ◽  
Effect Of Temperature ◽  
Salmo Gairdneri ◽  
Homeoviscous Adaptation ◽  
Cold Temperatures ◽  
Membrane Lipid Composition

The metabolic adjustments responsible for the “homeoviscous adaptation” of membrane lipid composition in fish are examined with special reference to the rainbow trout, Salmo gairdneri. The percentage of fatty acid lipogenesis attributable to unsaturates was elevated after an acute drop in temperature but declined with continued cold exposure (i.e., cold acclimation). In contrast, selected desaturation reactions [particularly those involved in the production of polyunsaturated fatty acids (PUFA) of the n-3 and/or n-6 families] proceeded more rapidly in cold-than in warm-acclimated trout. Different time courses for the change in monoene and PUFA levels of hepatic microsomal membranes during thermal acclimation suggest that the various desaturase enzymes contribute to the acclimatory response at different times. Certain fatty acids, particularly the delta 5-desaturation products of the n-3 (20:5 delta 5,8,11,14,17) and n-6 (20:4 delta 5,8,11,14) series, were preferentially incorporated into phospholipids at cold temperatures and by cold-acclimated trout, due in part to the direct effect of temperature on the substrate preferences of the phospho- and acyltransferase enzymes of de novo phospholipid biosynthesis; however, chain length rather than degree of unsaturation per se may determine the temperature-dependent pattern of fatty acid incorporation. Both acute and chronic cold exposure elevated the incorporation of PUFA into phosphatidylserine (PS), suggesting that the conversion of PS to phosphatidylethanolamine (PE) may be activated at cold temperatures. The rate of homeoviscous adaptation appears to be limited by the rate of membrane lipid turnover, which although generally positively correlated with acclimation temperature, did vary depending on the phospholipid moiety and tissue considered. Finally the direct acylation of lysophospholipids formed during the process of membrane turnover may contribute to both rapid and acclimatory adjustments in membrane lipid composition.

scholarly journals Cell membranes. Molecular lipid therapy

2017 ◽  
Vol 71 ◽  
pp. 1239-1250
Author(s):  
Anna Walczewska ◽  
Barbara Dziedzic ◽  
Dawid Stulczewski ◽  
Emilia Zgórzyńska
Keyword(s):  
Lipid Composition ◽  
Protein Function ◽  
Membrane Lipids ◽  
Transmembrane Protein ◽  
Functional Characteristic ◽  
Membrane Lipid ◽  
Molecular Structures ◽  
Membrane Microdomains ◽  
Membrane Lipid Composition ◽  
Wide Range

Membrane lipids, due to diverse molecular structures, electric charge and different functional characteristic, have a profound role in multiple cytophysiological processes. A better understanding of the membrane structure and changes of its function in a wide range of diseases gave rise to a new approach termed membrane lipid therapy and directed to modifying the membranes. The strategies directed to membrane involve a direct regulation of membrane lipid composition that causes a change of the transmembrane protein function and modifies the organization of membrane microdomains, or regulation of enzyme activity and gene expression to alter membrane lipid composition. Membrane therapy assumes the use of new molecules specifically designed to modify lipid composition and function of abnormal signaling proteins. Therefore, modifications of the lipid composition and organization of membrane microdomains become pharmacological targets to reverse pathological changes in the profile of enzymatically and non-enzymatically generated lipid derivatives or to modify signaling pathways in the cell. The present monography is an update of the canonical membrane model by Singer-Nicolson and describes the therapeutic targets related to the regulation of the composition and organization of the lipids in the plasma membrane.

scholarly journals Class II PI3Ks at the Intersection between Signal Transduction and Membrane Trafficking

Biomolecules ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 104 ◽  
Author(s):  
Jean Piero Margaria ◽  
Edoardo Ratto ◽  
Luca Gozzelino ◽  
Huayi Li ◽  
Emilio Hirsch
Keyword(s):  
Signal Transduction ◽  
Membrane Trafficking ◽  
Lipid Composition ◽  
Intracellular Signaling ◽  
Class Ii ◽  
Membrane Lipid ◽  
Membrane Lipid Composition ◽  
Inositol Phospholipids ◽  
Wide Range ◽  
And Migration

Phosphorylation of inositol phospholipids by the family of phosphoinositide 3-kinases (PI3Ks) is crucial in controlling membrane lipid composition and regulating a wide range of intracellular processes, which include signal transduction and vesicular trafficking. In spite of the extensive knowledge on class I PI3Ks, recent advances in the study of the three class II PI3Ks (PIK3C2A, PIK3C2B and PIK3C2G) reveal their distinct and non-overlapping cellular roles and localizations. By finely tuning membrane lipid composition in time and space among different cellular compartments, this class of enzymes controls many cellular processes, such as proliferation, survival and migration. This review focuses on the recent developments regarding the coordination of membrane trafficking and intracellular signaling of class II PI3Ks through the confined phosphorylation of inositol phospholipids.

Sign in / Sign up

Export Citation Format

Share Document