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Molecular & Cellular Proteomics : MCP Feb 2022Mammalian phospholipase D (PLD) enzyme family consists of six members. Among them, PLD1/2/6 catalyzes phosphatidic acid (PA) production, while PLD3/4/5 has no catalytic...
Mammalian phospholipase D (PLD) enzyme family consists of six members. Among them, PLD1/2/6 catalyzes phosphatidic acid (PA) production, while PLD3/4/5 has no catalytic activities. Deregulation of the PLD-PA lipid signaling has been associated with various human diseases including cancer. However, a comprehensive analysis of the regulators and effectors for this crucial lipid metabolic pathway has not been fully achieved. Using a proteomic approach, we defined the protein interaction network for the human PLD family of enzymes and PA and revealed diverse cellular signaling events involving them. Through it, we identified PJA2 as a novel E3 ubiquitin ligase for PLD1 involved in control of the PLD1-mediated mammalian target of rapamycin signaling. Additionally, we showed that PA interacted with and positively regulated sphingosine kinase 1. Taken together, our study not only generates a rich interactome resource for further characterizing the human PLD-PA lipid signaling but also connects this important metabolic pathway with numerous biological processes.
Topics: Humans; Phosphatidic Acids; Phospholipase D; Protein Interaction Maps; Proteomics; Signal Transduction
PubMed: 35007762
DOI: 10.1016/j.mcpro.2022.100195 -
Advances in Biological Regulation Jan 2019Lipid kinases regulate a wide variety of cellular functions and have emerged as one the most promising targets for drug design. Diacylglycerol kinases (DGKs) are a... (Review)
Review
Lipid kinases regulate a wide variety of cellular functions and have emerged as one the most promising targets for drug design. Diacylglycerol kinases (DGKs) are a family of enzymes that catalyze the ATP-dependent phosphorylation of diacylglycerol (DAG) to phosphatidic acid (PtdOH). Despite the critical role in lipid biosynthesis, both DAG and PtdOH have been shown as bioactive lipids mediating a number of signaling pathways. Although there is increasing recognition of their role in signaling systems, our understanding of the key enzyme which regulate the balance of these two lipid messages remain limited. Solved structures provide a wealth of information for understanding the function and regulation of these enzymes. Solving the structures of mammalian DGKs by traditional NMR and X-ray crystallography approaches have been challenging and so far, there are still no three-dimensional structures of these DGKs. Despite this, some insights may be gained by examining the similarities and differences between prokaryotic DGKs and other mammalian lipid kinases. This review focuses on summarizing and comparing the structure of prokaryotic and mammalian DGKs as well as two other lipid kinases: sphingosine kinase and phosphatidylinositol-3-kinase. How these known lipid kinases structures relate to mammalian DGKs will also be discussed.
Topics: Animals; Crystallography, X-Ray; Diacylglycerol Kinase; Diglycerides; Humans; Phosphatidic Acids; Phosphorylation; Protein Domains; Signal Transduction
PubMed: 30348515
DOI: 10.1016/j.jbior.2018.09.014 -
The Journal of Biological Chemistry Mar 2017Phosphatidic acid (PA) is the simplest phospholipid naturally existing in living organisms, but it constitutes only a minor fraction of total cell lipids. PA has... (Comparative Study)
Comparative Study
Phosphatidic acid (PA) is the simplest phospholipid naturally existing in living organisms, but it constitutes only a minor fraction of total cell lipids. PA has attracted considerable attention because it is a phospholipid precursor, a lipid second messenger, and a modulator of membrane shape, and it has thus been proposed to play key cellular functions. The dynamics of PA in cells and in subcellular compartments, however, remains an open question. The recent generation of fluorescent probes for PA, by fusing GFP to PA-binding domains, has provided direct evidence for PA dynamics in different intracellular compartments. Here, three PA sensors were characterized and their preferences for different PA species in particular lipidic environments were compared. In addition, the localization of PA in macrophages during frustrated phagocytosis was examined using these PA sensors and was combined with a lipidomic analysis of PA in intracellular compartments. The results indicate that the PA sensors display some preferences for specific PA species, depending on the lipid environment, and the localization study in macrophages revealed the complexity of intracellular PA dynamics.
Topics: Animals; Biosensing Techniques; Cell Membrane; Green Fluorescent Proteins; Humans; Lipids; Macrophages; Phagocytosis; Phosphatidic Acids; Recombinant Fusion Proteins; Second Messenger Systems
PubMed: 28115519
DOI: 10.1074/jbc.M116.742346 -
Advances in Biological Regulation Jan 2018In cortical and hippocampal neurons of the mammalian brain, the synaptic vesicle cycle is a series of steps that tightly regulate exo- and endocytosis of vesicles. Many... (Review)
Review
In cortical and hippocampal neurons of the mammalian brain, the synaptic vesicle cycle is a series of steps that tightly regulate exo- and endocytosis of vesicles. Many proteins contribute to this regulation, but lipids have recently emerged as critical regulators as well. Of all the many lipid signaling molecules, phosphatidic acid is important to the physical processes of membrane fusion. Therefore, the lipid-metabolizing enzymes that produce phosphatidic acid are vital to the regulation of the cycle. Our lab is particularly interested in the potential regulatory mechanisms and neuronal roles of two phosphatidic acid-producing enzymes: diacylglycerol kinase theta (DGKθ) and phospholipase D (PLD). We recently discovered a regulatory role of DGKθ on evoked endocytosis (Goldschmidt et al., 2016). In addition to this enzyme, studies implicate PLD1 in neurotransmission, although its precise role is of some debate. Altogether, the production of phosphatidic acid by these enzymes offer an interesting and novel pathway for the regulation of the synaptic vesicle cycle.
Topics: Animals; Endocytosis; Humans; Lipid Metabolism; Neurons; Phosphatidic Acids; Phospholipase D; Synaptic Transmission; Synaptic Vesicles
PubMed: 28986032
DOI: 10.1016/j.jbior.2017.09.009 -
Proceedings of the National Academy of... Feb 2023Lipids establish the specialized thylakoid membrane of chloroplast in eukaryotic photosynthetic organisms, while the molecular basis of lipid transfer from other...
Lipids establish the specialized thylakoid membrane of chloroplast in eukaryotic photosynthetic organisms, while the molecular basis of lipid transfer from other organelles to chloroplast remains further elucidation. Here we revealed the structural basis of Sec14 homology proteins AtSFH5 and AtSFH7 in transferring phosphatidic acid (PA) from endoplasmic reticulum (ER) to chloroplast, and whose function in regulating the lipid composition of chloroplast and thylakoid development. AtSFH5 and AtSFH7 localize at both ER and chloroplast, whose deficiency resulted in an abnormal chloroplast structure and a decreased thickness of stacked thylakoid membranes. We demonstrated that AtSFH5, but not yeast and human Sec14 proteins, could specifically recognize and transfer PA in vitro. Crystal structures of the AtSFH5-Sec14 domain in complex with L-α-phosphatidic acid (L-α-PA) and 1,2-dipalmitoyl-sn-glycero-3-phosphate (DPPA) revealed that two PA ligands nestled in the central cavity with different configurations, elucidating the specific binding mode of PA to AtSFH5, different from the reported phosphatidylethanolamine (PE)/phosphatidylcholine (PC)/phosphatidylinositol (PI) binding modes. Quantitative lipidomic analysis of chloroplast lipids showed that PA and monogalactosyldiacylglycerol (MGDG), particularly the C18 fatty acids at -2 position in MGDG were significantly decreased, indicating a disrupted ER-to-plastid (chloroplast) lipid transfer, under deficiency of AtSFH5 and AtSFH7. Our studies identified the role and elucidated the structural basis of plant SFH proteins in transferring PA between organelles, and suggested a model for ER-chloroplast interorganelle phospholipid transport from inherent ER to chloroplast derived from endosymbiosis of a cyanobacteriumproviding a mechanism involved in the adaptive evolution of cellular plastids.
Topics: Arabidopsis; Arabidopsis Proteins; Chloroplasts; Phosphatidic Acids; Thylakoids
PubMed: 36716376
DOI: 10.1073/pnas.2221637120 -
Plant, Cell & Environment May 2016Lipids are one of the major components of biological membranes including the plasma membrane, which is the interface between the cell and the environment. It has become... (Review)
Review
Lipids are one of the major components of biological membranes including the plasma membrane, which is the interface between the cell and the environment. It has become clear that membrane lipids also serve as substrates for the generation of numerous signalling lipids such as phosphatidic acid, phosphoinositides, sphingolipids, lysophospholipids, oxylipins, N-acylethanolamines, free fatty acids and others. The enzymatic production and metabolism of these signalling molecules are tightly regulated and can rapidly be activated upon abiotic stress signals. Abiotic stress like water deficit and temperature stress triggers lipid-dependent signalling cascades, which control the expression of gene clusters and activate plant adaptation processes. Signalling lipids are able to recruit protein targets transiently to the membrane and thus affect conformation and activity of intracellular proteins and metabolites. In plants, knowledge is still scarce of lipid signalling targets and their physiological consequences. This review focuses on the generation of signalling lipids and their involvement in response to abiotic stress. We describe lipid-binding proteins in the context of changing environmental conditions and compare different approaches to determine lipid-protein interactions, crucial for deciphering the signalling cascades.
Topics: Lipid Metabolism; Phosphatidic Acids; Plant Proteins; Plants; Signal Transduction; Stress, Physiological
PubMed: 26510494
DOI: 10.1111/pce.12666 -
Journal of Neurochemistry Nov 2022Major depressive disorder (MDD) is a severe disease of unknown pathogenesis with a lifetime prevalence of ~10%. Therapy requires prolonged treatment that often fails. We...
Major depressive disorder (MDD) is a severe disease of unknown pathogenesis with a lifetime prevalence of ~10%. Therapy requires prolonged treatment that often fails. We have previously demonstrated that ceramide levels in the blood plasma of patients and in mice with experimental MDD are increased. Neutralization of blood plasma ceramide prevented experimental MDD in mice. Mechanistically, we demonstrated that blood plasma ceramide accumulated in endothelial cells of the hippocampus, inhibited phospholipase D (PLD) and thereby decreased phosphatidic acid in the hippocampus. Here, we demonstrate that phosphatidic acid binds to and controls the activity of phosphotyrosine phosphatase (PTP1B) in the hippocampus and thus determines tyrosine phosphorylation of a variety of cellular proteins including TrkB. Injection of PLD, phosphatidic acid, or inhibition of PTP1B abrogated MDD and normalized cellular tyrosine phosphorylation, including phosphorylation of TrkB and neurogenesis in the hippocampus. Most importantly, these treatments also rapidly normalized behavior of mice with experimental MDD. Since phosphatidic acid binds to and inhibits PTP1B, the lack of phosphatidic acid results in increased activity of PTP1B and thereby in reduced tyrosine phosphorylation of TrkB and other cellular proteins. Thus, our data indicate a novel pathogenetic mechanism of and a rapidly acting targeted treatment for MDD.
Topics: Mice; Animals; Phosphatidic Acids; Depressive Disorder, Major; Endothelial Cells; Phosphorylation; Ceramides; Tyrosine
PubMed: 36227646
DOI: 10.1111/jnc.15708 -
Acta Biochimica Polonica 2018Phosphatidic acid (PA) is the simplest glycerophospholipid naturally occurring in living organisms, and even though its content among other cellular lipids is minor, it... (Review)
Review
Phosphatidic acid (PA) is the simplest glycerophospholipid naturally occurring in living organisms, and even though its content among other cellular lipids is minor, it is drawing more and more attention due to its multiple biological functions. PA is a precursor for other phospholipids, acts as a lipid second messenger and, due to its structural properties, is also a modulator of membrane shape. Although much is known about interaction of PA with its effectors, the molecular mechanisms remain unresolved to a large degree. Throughout many of the well-characterized PA cellular sensors, no conserved binding domain can be recognized. Moreover, not much is known about the cellular dynamics of PA and how it is distributed among subcellular compartments. Remarkably, PA can play distinct roles within each of these compartments. For example, in the nucleus it behaves as a mitogen, influencing gene expression regulation, and in the Golgi membrane it plays a role in membrane trafficking. Here, we discuss how a biophysical experimental approach enabled PA behavior to be described in the context of a lipid bilayer and to what extent various physicochemical conditions may modulate the functional properties of this lipid. Understanding these aspects would help to unravel specific mechanisms of PA-driven membrane transformations and protein recruitment and thus would lead to a clearer picture of the biological role of PA.
Topics: Cell Compartmentation; Cell Membrane; Lipid Bilayers; Phosphatidic Acids
PubMed: 29913482
DOI: 10.18388/abp.2018_2592 -
The Journal of Biological Chemistry Oct 1995The present study was aimed at defining the chemotactic activity of phosphatidic acid, which is rapidly produced by phagocytes in response to chemotactic agonists.... (Comparative Study)
Comparative Study
The present study was aimed at defining the chemotactic activity of phosphatidic acid, which is rapidly produced by phagocytes in response to chemotactic agonists. Exogenously added phosphatidic acid induced human monocyte directional migration across polycarbonate filters with an efficacy (number of cell migrated) comparable to that of "classical" chemotactic factors. In lipid specificity studies, activity of phosphatidic acid decreased with increasing acyl chain length but was restored by introducing unsaturation in the acyl chain with the most active form being the natural occurring 18:0,20:4-phosphatidic acid. Lysophosphatidic acid was also active in inducing monocyte migration. No other phospholipid and lysophospholipid tested was effective in this response. Monocyte migration was regulated by a gradient of phosphatidic acid and lysophosphatidic acid bound to the polycarbonate filter, in the absence of detectable soluble chemoattractant. Migration was also observed if phospholipids were bound to fibronectin-coated polycarbonate filters. Thus, phosphatidic acid and lysophosphatidic acid, similarly to other physiological chemoattractants (e.g. C5a and interleukin-8), induce cell migration by an haptotactic mechanism. Phosphatidic acid caused a rapid increase of filamentous actin and, at higher concentrations, induced a rise of intracellular calcium concentration. Monocyte migration to phosphatidic acid and lysophosphatidic acid, but not to diacylglycerol, was inhibited in a concentration-dependent manner by Bordetella pertussis toxin, while cholera toxin was ineffective. In the chemotactic assay, phosphatidic acid and lysophosphatidic acid induced a complete homologous desensitization and only partially cross-desensitized one with each other, or with diacyl-glycerol and monocyte chemotactic protein-1. Suramine inhibited monocyte chemotaxis with a different efficiency phosphatidic acid > lysophosphatidic acid" diacyl-glycerol On the contrary, monocyte chemotactic protein-1-induced chemotaxis was not affected by the drug. Collectively, these data show that phosphatidic acid induces haptotactic migration of monocytes that is at least in part receptor-mediated. These results support a role for phosphatidic acid and lysophosphatidic acid in the regulation of leukocyte accumulation into tissues.
Topics: Actins; Calcium; Chemokine CCL2; Chemotaxis, Leukocyte; Cholera Toxin; Dose-Response Relationship, Drug; Humans; Lysophospholipids; Monocytes; Pertussis Toxin; Phosphatidic Acids; Suramin; Virulence Factors, Bordetella
PubMed: 7592725
DOI: 10.1074/jbc.270.43.25549 -
Cell Reports Aug 2020Specific forms of fatty acids are well known to have beneficial health effects, but their precise mechanism of action remains elusive. Phosphatidic acid (PA) produced by...
Specific forms of fatty acids are well known to have beneficial health effects, but their precise mechanism of action remains elusive. Phosphatidic acid (PA) produced by phospholipase D1 (PLD1) regulates the sequential stages underlying secretory granule exocytosis in neuroendocrine chromaffin cells, as revealed by pharmacological approaches and genetic mouse models. Lipidomic analysis shows that secretory granule and plasma membranes display distinct and specific composition in PA. Secretagogue-evoked stimulation triggers the selective production of several PA species at the plasma membrane near the sites of active exocytosis. Rescue experiments in cells depleted of PLD1 activity reveal that mono-unsaturated PA restores the number of exocytotic events, possibly by contributing to granule docking, whereas poly-unsaturated PA regulates fusion pore stability and expansion. Altogether, this work provides insight into the roles that subspecies of the same phospholipid may play based on their fatty acyl chain composition.
Topics: Animals; Exocytosis; Humans; Mice; Neuroendocrine Cells; Phosphatidic Acids
PubMed: 32814056
DOI: 10.1016/j.celrep.2020.108026