scholarly journals Four Acyltransferases Uniquely Contribute to Phospholipid Heterogeneity in Saccharomyces cerevisiae

2016 ◽  
Vol 9 ◽  
pp. LPI.S40597 ◽  
Author(s):  
Peter Oelkers ◽  
Keshav Pokhrel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acyl Chain ◽  
Wild Type ◽  
Acid Incorporation ◽  
Rich Media ◽  
Chain Composition ◽  
Acyl Chain Composition ◽  
Acyl Chains ◽  
Phospholipid Acyl Chain

Diverse acyl-CoA species and acyltransferase isoenzymes are components of a complex system that synthesizes glycerophospholipids and triacylglycerols. Saccharomyces cerevisiae has four main acyl-CoA species, two main glycerol-3-phosphate 1- O-acyltransferases (Gat1p, Gat2p), and two main 1-acylglycerol-3-phosphate O-acyltransferases (Lpt1p, Slc1p). The in vivo contribution of these isoenzymes to phospholipid heterogeneity was determined using haploids with compound mutations: gat1Δlpt1Δ, gat2Δlpt1Δ, gat1Δslc1Δ, and gat2Δslc1Δ. All mutations mildly reduced [3H]palmitic acid incorporation into phospholipids relative to triacylglycerol. Electrospray ionization tandem mass spectrometry identified few differences from wild type in gat1Δlpt1Δ, dramatic differences in gat2Δslc1Δ, and intermediate changes in gat2Δlpt1Δ and gat1Δslc1Δ. Yeast expressing Gat1p and Lpt1p had phospholipids enriched with acyl chains that were unsaturated, 18 carbons long, and paired for length. These alterations prevented growth at 18.5°C and in 10% ethanol. Therefore, Gat2p and Slc1p dictate phospholipid acyl chain composition in rich media at 30°C. Slc1p selectively pairs acyl chains of different lengths.

scholarly journals The effect of membrane phospholipid acyl-chain composition on the activity of brain-β-N-acetyl-d-glucosaminidase

1981 ◽  
Vol 195 (2) ◽  
pp. 383-388 ◽  
Author(s):  
A Orlacchio ◽  
C Maffei ◽  
L Binaglia ◽  
G Porcellati
Keyword(s):  
Activation Energy ◽  
Membrane Fraction ◽  
Arrhenius Plot ◽  
Acyl Chain ◽  
Membrane Phospholipid ◽  
Chain Composition ◽  
Acyl Chain Composition ◽  
Membrane Bound ◽  
Phospholipid Acyl Chain ◽  
The Relationship

The phospholipid acyl-chain dependence of the membrane-bound lysosomal beta-N-acetyl-D-glucosaminidase has been examined on control membranes from rat brain primary cell cultures and on membrane modified by culturing the cells in media supplemented with polyunsaturated fatty acids. The relationship between beta-N-acetyl-D-glucosaminidase activity and the membrane phospholipid acyl-chain composition has been evaluated. An increase in the unsaturation level of phosphatidyl ethanolamines and phosphatidylcholines, the most abundant phospholipids in this membrane fraction, is related to the rate of the enzymic reaction. The Arrhenius plot of the enzyme activity in modified membranes shows break-temperatures, starting from approximately 15 degrees C. The apparent activation energy below and above the break-temperature is not correlated with phospholipid acyl-chain unsaturation.

scholarly journals The Effect of High Density Lipoprotein Phospholipid Acyl Chain Composition on the Efflux of Cellular Free Cholesterol

1995 ◽  
Vol 270 (11) ◽  
pp. 5882-5890 ◽  
Author(s):  
W. Sean Davidson ◽  
Kristin L. Gillotte ◽  
Sissel Lund-Katz ◽  
William J. Johnson ◽  
George H. Rothblat ◽  
...  
Keyword(s):  
High Density Lipoprotein ◽  
Free Cholesterol ◽  
Acyl Chain ◽  
Density Lipoprotein ◽  
High Density ◽  
Chain Composition ◽  
Acyl Chain Composition ◽  
Phospholipid Acyl Chain

scholarly journals Depletion of Phosphatidylcholine in Yeast Induces Shortening and Increased Saturation of the Lipid Acyl Chains: Evidence for Regulation of Intrinsic Membrane Curvature in a Eukaryote

2006 ◽  
Vol 17 (2) ◽  
pp. 1006-1017 ◽  
Author(s):  
Henry A. Boumann ◽  
Jacob Gubbens ◽  
Martijn C. Koorengevel ◽  
Chan-Seok Oh ◽  
Charles E. Martin ◽  
...  
Keyword(s):  
Regulatory Mechanism ◽  
Lipid Fraction ◽  
Acyl Chain ◽  
Membrane Curvature ◽  
Degree Of Saturation ◽  
Optimal Range ◽  
Double Deletion ◽  
Chain Composition ◽  
Acyl Chain Composition ◽  
Acyl Chains

To study the consequences of depleting the major membrane phospholipid phosphatidylcholine (PC), exponentially growing cells of a yeast cho2opi3 double deletion mutant were transferred from medium containing choline to choline-free medium. Cell growth did not cease until the PC level had dropped below 2% of total phospholipids after four to five generations. Increasing contents of phosphatidylethanolamine (PE) and phosphatidylinositol made up for the loss of PC. During PC depletion, the remaining PC was subject to acyl chain remodeling with monounsaturated species replacing diunsaturated species, as shown by mass spectrometry. The remodeling of PC did not require turnover by the SPO14-encoded phospholipase D. The changes in the PC species profile were found to reflect an overall shift in the cellular acyl chain composition that exhibited a 40% increase in the ratio of C16 over C18 acyl chains, and a 10% increase in the degree of saturation. The shift was stronger in the phospholipid than in the neutral lipid fraction and strongest in the species profile of PE. The shortening and increased saturation of the PE acyl chains were shown to decrease the nonbilayer propensity of PE. The results point to a regulatory mechanism in yeast that maintains intrinsic membrane curvature in an optimal range.

scholarly journals How is the acyl chain composition of phosphoinositides created and does it matter?

2019 ◽  
Vol 47 (5) ◽  
pp. 1291-1305 ◽  
Author(s):  
David Barneda ◽  
Sabina Cosulich ◽  
Len Stephens ◽  
Phillip Hawkins
Keyword(s):  
Cell Biology ◽  
Acyl Chain ◽  
Effector Proteins ◽  
Selective Enrichment ◽  
Binding Domains ◽  
Chain Composition ◽  
Acyl Chain Composition ◽  
Phosphorylation Pattern ◽  
Acyl Chains ◽  
Membrane Cell

Abstract The phosphoinositide (PIPn) family of signalling phospholipids are central regulators in membrane cell biology. Their varied functions are based on the phosphorylation pattern of their inositol ring, which can be recognized by selective binding domains in their effector proteins and be modified by a series of specific PIPn kinases and phosphatases, which control their interconversion in a spatial and temporal manner. Yet, a unique feature of PIPns remains largely unexplored: their unusually uniform acyl chain composition. Indeed, while most phospholipids present a range of molecular species comprising acyl chains of diverse length and saturation, PIPns in several organisms and tissues show the predominance of a single hydrophobic backbone, which in mammals is composed of arachidonoyl and stearoyl chains. Despite evolution having favoured this specific PIPn configuration, little is known regarding the mechanisms and functions behind it. In this review, we explore the metabolic pathways that could control the acyl chain composition of PIPns as well as the potential roles of this selective enrichment. While our understanding of this phenomenon has been constrained largely by the technical limitations in the methods traditionally employed in the PIPn field, we believe that the latest developments in PIPn analysis should shed light onto this old question.

scholarly journals Acyl-chain saturation regulates the order of phosphatidylinositol 4,5-bisphosphate nanodomains

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Luís Borges-Araújo ◽  
Marco M. Domingues ◽  
Alexander Fedorov ◽  
Nuno C. Santos ◽  
Manuel N. Melo ◽  
...  
Keyword(s):  
Negative Curvature ◽  
Acyl Chain ◽  
Critical Role ◽  
Chain Structure ◽  
Membrane Remodeling ◽  
Biophysical Properties ◽  
Chain Composition ◽  
Acyl Chain Composition ◽  
Acyl Chains ◽  
The Impact

AbstractPhosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) plays a critical role in the regulation of various plasma membrane processes and signaling pathways in eukaryotes. A significant amount of cellular resources are spent on maintaining the dominant 1-stearoyl-2-arachidonyl PI(4,5)P2 acyl-chain composition, while less abundant and more saturated species become more prevalent in response to specific stimuli, stress or aging. Here, we report the impact of acyl-chain structure on the biophysical properties of cation-induced PI(4,5)P2 nanodomains. PI(4,5)P2 species with increasing levels of acyl-chain saturation cluster in progressively more ordered nanodomains, culminating in the formation of gel-like nanodomains for fully saturated species. The formation of these gel-like domains was largely abrogated in the presence of 1-stearoyl-2-arachidonyl PI(4,5)P2. This is, to the best of our knowledge, the first report of the impact of PI(4,5)P2 acyl-chain composition on cation-dependent nanodomain ordering, and provides important clues to the motives behind the enrichment of PI(4,5)P2 with polyunsaturated acyl-chains. We also show how Ca2+-induced PI(4,5)P2 nanodomains are able to generate local negative curvature, a phenomenon likely to play a role in membrane remodeling events.

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