Phosphatidic Acid Production by Phospholipase D1 Enhances Translocation of Caveolin to a Perinuclear Compartment

The symbiosis in trypanosomatids is a mutualistic relationship characterized by extensive metabolic exchanges between the bacterium and the protozoan. The symbiotic bacterium can complete host essential metabolic pathways, such as those for heme, amino acid, and vitamin production. Experimental assays indicate that the symbiont acquires phospholipids from the host trypanosomatid, especially phosphatidylcholine, which is often present in bacteria that have a close association with eukaryotic cells. In this work, an in-silico study was performed to find genes involved in the glycerophospholipid (GPL) production of Symbiont Harboring Trypanosomatids (SHTs) and their respective bacteria, also extending the search for trypanosomatids that naturally do not have symbionts. Results showed that most genes for GPL synthesis are only present in the SHT. The bacterium has an exclusive sequence related to phosphatidylglycerol production and contains genes for phosphatidic acid production, which may enhance SHT phosphatidic acid production. Phylogenetic data did not indicate gene transfers from the bacterium to the SHT nucleus, proposing that enzymes participating in GPL route have eukaryotic characteristics. Taken together, our data indicate that, differently from other metabolic pathways described so far, the symbiont contributes little to the production of GPLs and acquires most of these molecules from the SHT.

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Phospholipase D1-generated phosphatidic acid modulates secretory granule trafficking from biogenesis to compensatory endocytosis in neuroendocrine cells

Advances in Biological Regulation ◽

10.1016/j.jbior.2021.100844 ◽

2021 ◽

pp. 100844

Author(s):

Emeline Tanguy ◽

Alexander Wolf ◽

Qili Wang ◽

Sylvette Chasserot-Golaz ◽

Stéphane Ory ◽

...

Keyword(s):

Phosphatidic Acid ◽

Secretory Granule ◽

Neuroendocrine Cells ◽

Phospholipase D1

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Interaction of nitric oxide and cGMP with signal transduction in activated platelets

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1991.261.4.h1043 ◽

1991 ◽

Vol 261 (4) ◽

pp. H1043-H1052 ◽

Cited By ~ 16

Author(s):

B. L. Nguyen ◽

M. Saitoh ◽

J. A. Ware

Keyword(s):

Nitric Oxide ◽

Signal Transduction ◽

Platelet Aggregation ◽

Phosphatidic Acid ◽

Acid Production ◽

Human Platelets ◽

Serotonin Secretion ◽

A Cell ◽

Platelet Aggregates ◽

Pkc Activation

Although nitric oxide (NO), one of the endothelium-derived relaxing factors, prevents formation of platelet aggregates, the mechanism by which this occurs is not fully understood. Accordingly, the effect of NO on signal transduction of gel-filtered human platelets was measured and compared with that of a cell-permeant guanosine 3',5'-cyclic monophosphate (cGMP) analogue, 8-bromo-cGMP (8-BrcGMP). NO inhibited the rise in intracellular Ca2+ concentration ([Ca2+]i), phosphorylation of the 47-kDa substrate (p47) of protein kinase C (PKC), serotonin secretion, and phosphatidic acid production induced by thrombin or the endoperoxide analogue U-46619. Similar effects were seen with 8-BrcGMP, and NO induced a concentration-related rise in cGMP. Neither NO nor 8-BrcGMP inhibited platelet aggregation, [Ca2+]i mobilization, or serotonin secretion induced by the Ca2+ ionophores A23187 or ionomycin or directly activated PKC purified from platelets. However, both NO and 8-BrcGMP enhanced p47 phosphorylation induced by the Ca2+ ionophores without augmenting phosphatidic acid production. Thus, if [Ca2+]i is elevated, a rise in cGMP enhances PKC activation. Both NO and 8-BrcGMP, however, prevent Ca2+ mobilization and platelet aggregation induced by receptor-mediated agonists by interfering with signal transduction at a point proximal to phospholipase C activation.

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Phospholipase D1 regulates high-affinity IgE receptor-induced mast cell degranulation

Blood ◽

10.1182/blood-2004-06-2091 ◽

2004 ◽

Vol 104 (13) ◽

pp. 4122-4128 ◽

Cited By ~ 21

Author(s):

Tomohiro Hitomi ◽

Juan Zhang ◽

Liliana M. Nicoletti ◽

Ana Cristina G. Grodzki ◽

Maria C. Jamur ◽

...

Keyword(s):

Mast Cell ◽

Phosphatidic Acid ◽

Mast Cell Degranulation ◽

Dominant Negative ◽

Acid Formation ◽

Wild Type ◽

High Affinity ◽

Phospholipase D1 ◽

High Affinity Ige Receptor

Abstract To investigate the role of phospholipase D (PLD) in FcϵRI signaling, the wild-type or the catalytically inactive forms of PLD1 or PLD2 were stably overexpressed in RBL-2H3 mast cells. FcϵRI stimulation resulted in the activation of both PLD1 and PLD2. However, PLD1 was the source of most of the receptor-induced PLD activity. There was enhanced FcϵRI-induced degranulation only in cells that overexpressed the catalytically inactive PLD1. This dominant-negative PLD1 enhanced FcϵRI-induced tyrosine phosphorylations of early signaling molecules such as the receptor subunits, Syk and phospholipase C-γ which resulted in faster release of Ca2+ from intracellular sources. Therefore, PLD1 negatively regulates signals upstream of the Ca2+ response. However, FcϵRI-induced PLD activation required Syk and was downstream of the Ca2+response, suggesting that basal PLD1 activity rather than that activated by cell stimulation controlled these early signaling events. Dominant-negative PLD1 reduced the basal phosphatidic acid formation in unstimulated cells, which was accompanied by an increase in FcϵRI within the lipid rafts. These results indicate that constitutive basal PLD1 activity by regulating phosphatidic acid formation controls the early signals initiated by FcϵRI aggregation that lead to mast cell degranulation. (Blood. 2004;104:4122-4128)

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