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International Journal of Molecular... Mar 2022Cells sense a variety of extracellular signals balancing their metabolism and physiology according to changing growth conditions. Plasma membranes are the outermost... (Review)
Review
Cells sense a variety of extracellular signals balancing their metabolism and physiology according to changing growth conditions. Plasma membranes are the outermost informational barriers that render cells sensitive to regulatory inputs. Membranes are composed of different types of lipids that play not only structural but also informational roles. Hormones and other regulators are sensed by specific receptors leading to the activation of lipid metabolizing enzymes. These enzymes generate lipid second messengers. Among them, phosphatidic acid (PA) is a well-known intracellular messenger that regulates various cellular processes. This lipid affects the functional properties of cell membranes and binds to specific target proteins leading to either genomic (affecting transcriptome) or non-genomic responses. The subsequent biochemical, cellular and physiological reactions regulate plant growth, development and stress tolerance. In the present review, we focus on primary (genome-independent) signaling events triggered by rapid PA accumulation in plant cells and describe the functional role of PA in mediating response to hormones and hormone-like regulators. The contributions of individual lipid signaling enzymes to the formation of PA by specific stimuli are also discussed. We provide an overview of the current state of knowledge and future perspectives needed to decipher the mode of action of PA in the regulation of cell functions.
Topics: Hormones; Phosphatidic Acids; Phospholipase D; Plant Development; Plant Proteins; Plants; Proteins; Signal Transduction
PubMed: 35328648
DOI: 10.3390/ijms23063227 -
Biochimica Et Biophysica Acta.... Oct 2019Lipins are phosphatidic acid phosphatase enzymes whose cellular function in regulating lipid metabolism has been known for decades, particularly in metabolically active... (Review)
Review
Lipins are phosphatidic acid phosphatase enzymes whose cellular function in regulating lipid metabolism has been known for decades, particularly in metabolically active tissues such as adipose tissue or liver. In recent years evidence is accumulating for key regulatory roles of the lipin family in innate immune cells. Lipins may help regulate signaling through relevant immune receptors such as Toll-like receptors, and are also integral part of the cellular machinery for lipid storage in these cells, thereby modulating certain inflammatory processes. Mutations in genes that encode for members of this family produce autoinflammatory hereditary diseases or diseases with an important inflammatory component in humans. In this review we summarize recent findings on the role of lipins in cells of the innate immune system and in the onset and progress of inflammatory processes.
Topics: Animals; Diglycerides; Humans; Immunity, Innate; Inflammation; Macrophages; Phosphatidate Phosphatase; Phosphatidic Acids
PubMed: 31220616
DOI: 10.1016/j.bbalip.2019.06.003 -
Trends in Biochemical Sciences Jun 2019In eukaryotes, organelles and vesicles modulate their contents and identities through highly regulated membrane fusion events. Membrane trafficking and fusion are... (Review)
Review
In eukaryotes, organelles and vesicles modulate their contents and identities through highly regulated membrane fusion events. Membrane trafficking and fusion are carried out through a series of stages that lead to the formation of SNARE complexes between cellular compartment membranes to trigger fusion. Although the protein catalysts of membrane fusion are well characterized, their response to their surrounding microenvironment, provided by the lipid composition of the membrane, remains to be fully understood. Membranes are composed of bulk lipids (e.g., phosphatidylcholine), as well as regulatory lipids that undergo constant modifications by kinases, phosphatases, and lipases. These lipids include phosphoinositides, diacylglycerol, phosphatidic acid, and cholesterol/ergosterol. Here we describe the roles of these lipids throughout the stages of yeast vacuole homotypic fusion.
Topics: Cholesterol; Ergosterol; Glycerides; Humans; Membrane Fusion; Phosphatidic Acids; Phosphatidylinositols; Vacuoles
PubMed: 30587414
DOI: 10.1016/j.tibs.2018.12.003 -
The Journal of Biological Chemistry Sep 2016Caveolae are the primary route for internalization and transendothelial transport of macromolecules, such as insulin and albumin. Caveolae-mediated endocytosis is...
Caveolae are the primary route for internalization and transendothelial transport of macromolecules, such as insulin and albumin. Caveolae-mediated endocytosis is activated by Src-dependent caveolin-1 (Cav-1) phosphorylation and subsequent recruitment of dynamin-2 and filamin A (FilA), which facilitate vesicle fission and trafficking, respectively. Here, we tested the role of RalA and phospholipase D (PLD) signaling in the regulation of caveolae-mediated endocytosis and trafficking. The addition of albumin to human lung microvascular endothelial cells induced the activation of RalA within minutes, and siRNA-mediated down-regulation of RalA abolished fluorescent BSA uptake. Co-immunoprecipitation studies revealed that albumin induced the association between RalA, Cav-1, and FilA; however, RalA knockdown with siRNA did not affect FilA recruitment to Cav-1, suggesting that RalA was not required for FilA and Cav-1 complex formation. Rather, RalA probably facilitates caveolae-mediated endocytosis by activating downstream effectors. PLD2 was shown to be activated by RalA, and inhibition of PLD2 abolished Alexa-488-BSA uptake, indicating that phosphatidic acid (PA) generated by PLD2 may facilitate caveolae-mediated endocytosis. Furthermore, using a PA biosensor, GFP-PASS, we observed that BSA induced an increase in PA co-localization with Cav-1-RFP, which could be blocked by a dominant negative PLD2 mutant. Total internal reflection fluorescence microscopy studies of Cav-1-RFP also showed that fusion of caveolae with the basal plasma membrane was dependent on PLD2 activity. Thus, our results suggest that the small GTPase RalA plays an important role in promoting invagination and trafficking of caveolae, not by potentiating the association between Cav-1 and FilA but by stimulating PLD2-mediated generation of phosphatidic acid.
Topics: Biological Transport, Active; Caveolae; Cell Membrane; Endocytosis; Endothelial Cells; Humans; Mutation; Phosphatidic Acids; Phospholipase D; ral GTP-Binding Proteins
PubMed: 27510034
DOI: 10.1074/jbc.M116.752485 -
Plant Signaling & Behavior 2014Transport of proteins containing a nuclear localization signal (NLS) into the nucleus is mediated by nuclear transport receptors called importins, typically dimmers of a...
Transport of proteins containing a nuclear localization signal (NLS) into the nucleus is mediated by nuclear transport receptors called importins, typically dimmers of a cargo-binding α-subunit and a β-subunit that mediates translocation through the nuclear pore complexes (NPCs). However, how proteins without canonical NLS move into the nucleus is not well understood. Recent results indicate that phospholipids, such as phosphatidic acid, play important roles in the intracellular translocation of proteins between the nucleus and cytoplasm.
Topics: Active Transport, Cell Nucleus; Arabidopsis; Arabidopsis Proteins; Cell Nucleus; Intracellular Space; Models, Biological; Nuclear Localization Signals; Phosphatidic Acids; Receptors, Cell Surface
PubMed: 25482760
DOI: 10.4161/15592324.2014.977711 -
Cellular and Molecular Life Sciences :... Oct 2005Phospholipase D (PLD) hydrolyzes the phosphodiester bond of the glycerolipid phosphatidylcholine, resulting in the production of phosphatidic acid and free choline.... (Review)
Review
Phospholipase D (PLD) hydrolyzes the phosphodiester bond of the glycerolipid phosphatidylcholine, resulting in the production of phosphatidic acid and free choline. Phosphatidic acid is widely considered to be the intracellular lipid mediator of many of the biological functions attributed to PLD. However, phosphatidic acid is a tightly regulated lipid in cells and can be converted to other potentially bioactive lipids, including diacylglycerol and lysophosphatidic acid. PLD activities have been described in multiple organisms, including plants, mammals, bacteria and yeast. In mammalian systems, PLD activity regulates the actin cytoskeleton, vesicle trafficking for secretion and endocytosis, and receptor signaling. PLD is in turn regulated by phosphatidylinositol-4,5-bisphosphate, protein kinase C and ADP Ribosylation Factor and Rho family GTPases. This review focuses on the lipid precursors and products of mammalian PLD metabolism, especially phosphatidic acid and the roles this lipid performs in the mediation of the functions of PLD.
Topics: Animals; Lipid Metabolism; Phosphatidic Acids; Phospholipase D
PubMed: 16143829
DOI: 10.1007/s00018-005-5195-z -
The Journal of Biological Chemistry May 2011The exposure of the plasma membrane calcium pump (PMCA) to the surrounding phospholipids was assessed by measuring the incorporation of the photoactivatable...
The exposure of the plasma membrane calcium pump (PMCA) to the surrounding phospholipids was assessed by measuring the incorporation of the photoactivatable phosphatidylcholine analog [(125)I]TID-PC/16 to the protein. In the presence of Ca(2+) both calmodulin (CaM) and phosphatidic acid (PA) greatly decreased the incorporation of [(125)I]TID-PC/16 to PMCA. Proteolysis of PMCA with V8 protease results in three main fragments: N, which includes transmembrane segments M1 and M2; M, which includes M3 and M4; and C, which includes M5 to M10. CaM decreased the level of incorporation of [(125)I]TID-PC/16 to fragments M and C, whereas phosphatidic acid decreased the incorporation of [(125)I]TID-PC/16 to fragments N and M. This suggests that the conformational changes induced by binding of CaM or PA extend to the adjacent transmembrane domains. Interestingly, this result also denotes differences between the active conformations produced by CaM and PA. To verify this point, we measured resonance energy transfer between PMCA labeled with eosin isothiocyanate at the ATP-binding site and the phospholipid RhoPE included in PMCA micelles. CaM decreased the efficiency of the energy transfer between these two probes, whereas PA did not. This result indicates that activation by CaM increases the distance between the ATP-binding site and the membrane, but PA does not affect this distance. Our results disclose main differences between PMCA conformations induced by CaM or PA and show that those differences involve transmembrane regions.
Topics: Adenosine Triphosphate; Binding Sites; Calmodulin; Enzyme Activation; Erythrocyte Membrane; Humans; Hydrophobic and Hydrophilic Interactions; Micelles; Phosphatidic Acids; Plasma Membrane Calcium-Transporting ATPases; Protein Structure, Tertiary
PubMed: 21454645
DOI: 10.1074/jbc.M110.210088 -
Planta Jun 2020The main source of polyunsaturated acyl-CoA in cytoplasmic acyl-CoA pool of Camelina sativa seeds are fatty acids derived from phosphatidylcholine followed by...
The main source of polyunsaturated acyl-CoA in cytoplasmic acyl-CoA pool of Camelina sativa seeds are fatty acids derived from phosphatidylcholine followed by phosphatidic acid. Contribution of phosphatidylethanolamine is negligible. While phosphatidylethanolamine (PE) is the second most abundant phospholipid, phosphatidic acid (PA) only constitutes a small fraction of C. sativa seeds' polar lipids. In spite of this, the relative contribution of PA in providing fatty acids for the synthesis of acyl-CoA, supplying cytosolic acyl-CoA pool seems to be much higher than the contribution of PE. Our data indicate that up to 5% of fatty acids present in mature C. sativa seeds are first esterified with PA, in comparison to 2% first esterified with PE, before being transferred into acyl-CoA pool via backward reactions of either acyl-CoA:lysophosphatidic acid acyltransferases (CsLPAATs) or acyl-CoA:lysophoshatidylethanolamine acyltransferases (CsLPEATs). Those acyl-CoAs are later reused for lipid biosynthesis or remodelling. In the forward reactions both aforementioned acyltransferases display the highest activity at 30 °C. The spectrum of optimal pH differs for both enzymes with CsLPAATs most active between pH 7.5-9.0 and CsLPEATs between pH 9.0 to 10.0. Whereas addition of magnesium ions stimulates CsLPAATs, calcium and potassium ions inhibit them in concentrations of 0.05-2.0 mM. All three types of ions inhibit CsLPEATs activity. Both tested acyltransferases present the highest preferences towards 16:0-CoA and unsaturated 18-carbon acyl-CoAs in forward reactions. However, CsLPAATs preferentially utilise 18:1-CoA and CsLPEATs preferentially utilise 18:2-CoA while catalysing fatty acid remodelling of PA and PE, respectively.
Topics: 1-Acylglycerophosphocholine O-Acyltransferase; Acyl Coenzyme A; Camellia; Fatty Acids; Lysophospholipids; Phosphatidic Acids; Phosphatidylcholines; Phosphatidylethanolamines; Seeds
PubMed: 32524208
DOI: 10.1007/s00425-020-03408-z -
Biomolecules Apr 2018Cellular membranes are composed of thousands of different lipids usually maintained within a narrow range of concentrations. In addition to their well-known structural... (Review)
Review
Cellular membranes are composed of thousands of different lipids usually maintained within a narrow range of concentrations. In addition to their well-known structural and metabolic roles, signaling functions for many lipids have also emerged over the last two decades. The latter largely depend on the ability of particular classes of lipids to interact specifically with a great variety of proteins and to regulate their localization and activity. Among these lipids, phosphatidic acid (PA) plays a unique role in a large repertoire of cellular activities, most likely in relation to its unique biophysical properties. However, until recently, only incomplete information was available to model the interaction between PA and its protein partners. The development of new liposome-based assays as well as molecular dynamic simulation are now providing novel information. We will review the different factors that have shown to modulate the capacity of PA to interact with specific domains in target proteins.
Topics: Animals; Cell Membrane; Humans; Phosphatidic Acids; Phospholipase D; Protein Binding; Static Electricity
PubMed: 29690573
DOI: 10.3390/biom8020020 -
Journal of Chromatography. A Apr 2022The use of hybrid surface technology (HST), applied to the metal surfaces of an ACQUITY™ UPLC™ system and column, designed to mitigate the chelation, poor peak shape...
The use of hybrid surface technology (HST), applied to the metal surfaces of an ACQUITY™ UPLC™ system and column, designed to mitigate the chelation, poor peak shape and analyte loss seen with acidic phospholipids was investigated. Compared to a conventional system significant improvements in both sensitivity, recovery and peak shape were obtained following UPLC on a CSH C18 column when the HST was used for the analysis of lysophosphatidic acid (LPA), phosphatidic acid (PA), lysophosphatidylserine (LPS), phosphatidylserine (PS), phosphatidylinositol-monophosphates (PIP), ceramide phosphate (CerP) and sphingoid base phosphate (SPBP). The benefits in chromatographic performance provided by the HST were seen particularly at low concentrations of these analytes. The HST system and column reduced peak tailing by 65-80% and peak width by 70-86% for LPA and PA. Moreover, increased signal intensities of up to 12.7 times were observed for LPA with the HST approach compared to the equivalent untreated LC system and column. The application of this methodology to the analysis of chicken egg PA and brain porcine PS extracts were accompanied by similar improvements in data quality.
Topics: Animals; Metals; Phosphatidic Acids; Phosphatidylinositols; Phosphatidylserines; Swine; Technology
PubMed: 35272103
DOI: 10.1016/j.chroma.2022.462921