Search results for "Phospholipase"
showing 10 items of 221 documents
A non-venomous sPLA2 of a lepidopteran insect: Its physiological functions in development and immunity
2018
Eicosanoids are oxygenated C20 polyunsaturated fatty acids that mediate various physiological processes in insects. Eicosanoid biosynthesis begins with a C20 precursor, arachidonic acid (5,8,11,14-eicosatetraenoic acid: AA). AA is usually released from phospholipids at sn-2 position by catalytic activity of phospholipase A2 (PLA2). Although various PLA2s classified into 16 gene families (= Groups) are known in various biological systems, few PLA2s are known in insects. Only two PLA2s involved in intracellular calcium independent PLA2 (iPLA2) group have been identified in lepidopteran insects with well known eicosanoid physiology. This study reports the first secretory PLA2 (sPLA2) in lepido…
The Role of Phospholipase D and MAPK Signaling Cascades in the Adaption of Lichen Microalgae to Desiccation: Changes in Membrane Lipids and Phosphopr…
2016
Classically, lichen phycobionts are described as poikilohydric organisms able to undergo desiccation due to the constitutive presence of molecular protection mechanisms. However, little is known about the induction of cellular responses in lichen phycobionts during drying. The analysis of the lipid composition of the desiccated lichen microalga Asterochloris erici revealed the unusual accumulation of highly polar lipids (oligogalactolipids and phosphatidylinositol), which prevents the fusion of membranes during stress, but also the active degradation of cone-shaped lipids (monogalactosyldiacylglycerol and phosphatidylethanolamine) to stabilize membranes in desiccated cells. The level of pho…
Ergosterol elicits oxidative burst in tobacco cells via phospholipase A2 and protein kinase C signal pathway
2004
Ergosterol, a typical fungal sterol, induced in tobacco (Nicotiana tabacum L. cv. Xanthi) suspension cells the synthesis of reactive oxygen species and alkalization of the external medium that are dependent on the mobilization of calcium from internal stores. We used specific inhibitors to elucidate the signal pathway triggered by ergosterol compared with cryptogein, a proteinaceous elicitor of Phytophthora cryptogea. HerbimycinA and genistein, inhibitors of tyrosine protein kinases, had no effect on the oxidative burst and pH changes induced by bothelicitors.Similarly,H-89,aninhibitorofproteinkinaseA,hadnoeffectontheinductionofthesedefensereactions.However,theresponse to both elicitors was…
Lipid composition of the vacuolar membrane of Acer pseudoplatanus cultured cells
1993
Tonoplast was prepared by osmotic lysis of a pure vacuolar fraction isolated from protoplasts derived from Acer pseudoplatanus cultured cells. After their extraction, neutral and polar lipids were separated by a thin layer chromatography. Phospholipids, glycolipids and neutral lipids represented 44.5%, 39.1% and 16.4% of total lipids, respectively. Sterols (glycosylated plus non-glycosylated forms) constituted 30.8% of total lipids; 75% of sterols were glycosylated. The most prominent lipids were phosphatidylethanolamine (20.8%), phosphatidylcholine (13.5%), ceramide monohexoside (12.8%), steryl glycoside (12.2%) and acylated steryl glycoside (10.9%). Glucose was the only sugar released by …
Phospholipase activities associated with the tonoplast from Acer pseudoplatanus cells: identification of a phospholipase A1 activity
1995
In higher plants, the lipolytic enzymes and their physiological functions are not well characterized [1]. Most reports demonstrated that phospholipid catabolism in plants is achieved by the concerted actions of membrane-bound enzymes including phospholipase D, phosphatidate phosphatase, lipolytic acyl hydrolases and lipoxygenases [1,2]. With the exception of the phospholipase D, the literature on plant phospholipases is still very limited. We previously reported that tonoplast from Acer pseudoplatanus cells contains small amounts of phosphatidc acid and lysophospholipids, which were produced together with free fatty acids, particularly after addition of Ca2+[3]. These data suggested the pos…
Chromosome-Encoded Hemolysin, Phospholipase, and Collagenase in Plasmidless Isolates of Photobacterium damselae subsp. damselae Contribute to Virulen…
2017
ABSTRACT Photobacterium damselae subsp. damselae is a pathogen of marine animals, including fish of importance in aquaculture. The virulence plasmid pPHDD1, characteristic of highly hemolytic isolates, encodes the hemolysins damselysin (Dly) and phobalysin (PhlyP). Strains lacking pPHDD1 constitute the vast majority of the isolates from fish outbreaks, but genetic studies to identify virulence factors in plasmidless strains are scarce. Here, we show that the chromosome I-encoded hemolysin PhlyC plays roles in virulence and cell toxicity in pPHDD1-negative isolates of this pathogen. By combining the analyses of whole genomes and of gene deletion mutants, we identified two hitherto uncharacte…
Postnatal development of the dopaminergic signaling involved in the modulation of intestinal motility in mice
2015
Background:Since antidopaminergic drugs are pharmacological agents employed in the management of gastrointestinal motor disorders at all ages, we investigated whether the enteric dopaminergic system may undergo developmental changes after birth.Methods:Intestinal mechanical activity was examined in vitro as changes in isometric tension.Results:In 2-d-old (P2) mice, dopamine induced a contractile effect, decreasing in intensity with age, replaced, at the weaning (day 20), by a relaxant response. Both responses were tetrodotoxin (TTX)-insensitive. In P2, dopaminergic contraction was inhibited by D1-like receptor antagonist and mimicked by D1-like receptor agonist. In 90-d-old (P90) mice, the …
Virus-encoded microRNA contributes to the molecular profile of EBV-positive Burkitt lymphomas
2015
Burkitt lymphoma (BL) is an aggressive neoplasm characterized by consistent morphology and phenotype, typical clinical behavior and distinctive molecular profile. The latter is mostly driven by the MYC over-expression associated with the characteristic translocation (8;14) (q24; q32) or with variant lesions. Additional genetic events can contribute to Burkitt Lymphoma pathobiology and retain clinical significance. A pathogenetic role for Epstein-Barr virus infection in Burkitt lymphomagenesis has been suggested; however, the exact function of the virus is largely unknown. In this study, we investigated the molecular profiles (genes and microRNAs) of Epstein-Barr virus-positive and -negative…
Simultaneous lipidomic and transcriptomic profiling in mouse brain punches of acute epileptic seizure model compared to controls
2018
In this study, we report the development of a dual extraction protocol for RNA and lipids, including phospholipids, endocannabinoids, and arachidonic acid, at high spatial resolution, e.g., brain punches obtained from whole frozen brains corresponding to four brain subregions: dorsal hippocampus, ventral hippocampus, basolateral amygdala, and hypothalamus. This extraction method combined with LC/multiple reaction monitoring for lipid quantification and quantitative PCR for RNA investigation allows lipidomic and transcriptomic profiling from submilligram amounts of tissue, thus benefiting the time and animal costs for analysis and the data reliability due to prevention of biological variabil…
The phospholipase DDHD1 as a new target in colorectal cancer therapy
2018
Background Our previous study demonstrates that Citrus-limon derived nanovesicles are able to decrease colon cancer cell viability, and that this effect is associated with the downregulation of the intracellular phospholipase DDHD domain-containing protein 1 (DDHD1). While few studies are currently available on the contribution of DDHD1 in neurological disorders, there is no information on its role in cancer. This study investigates the role of DDHD1 in colon cancer. Methods DDHD1 siRNAs and an overexpression vector were transfected into colorectal cancer and normal cells to downregulate or upregulate DDHD1 expression. In vitro and in vivo assays were performed to investigate the functional…