Expression, characterization, and crystallization of a member of the novel phospholipase D family of phosphodiesterases

Earlier, we reported that mercury, the environmental risk factor for cardiovascular diseases, activates vascular endothelial cell (EC) phospholipase D (PLD). Here, we report the novel and significant finding that calcium and calmodulin regulated mercury-induced PLD activation in bovine pulmonary artery ECs (BPAECs). Mercury (mercury chloride, 25 μM; thimerosal, 25 μM; methylmercury, 10 μM) significantly activated PLD in BPAECs. Calcium chelating agents and calcium depletion of the medium completely attenuated the mercury-induced PLD activation in ECs. Calmodulin inhibitors significantly attenuated mercury-induced PLD activation in BPAECs. Despite the absence of L-type calcium channels in ECs, nifedipine, nimodipine, and diltiazem significantly attenuated mercury-induced PLD activation and cytotoxicity in BPAECs. This study demonstrated the importance of calcium and calmodulin in the regulation of mercury-induced PLD activation and the protective action of L-type calcium channel blockers against mercury cytotoxicity in vascular ECs, suggesting mechanisms of mercury vasculotoxicity and mercury-induced cardiovascular diseases.

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Expression, Characterization, and Mutagenesis of theYersinia pestisMurine Toxin, a Phospholipase D Superfamily Member

Journal of Biological Chemistry ◽

10.1074/jbc.274.17.11824 ◽

1999 ◽

Vol 274 (17) ◽

pp. 11824-11831 ◽

Cited By ~ 81

Author(s):

Amy E. Rudolph ◽

Jeanne A. Stuckey ◽

Yi Zhao ◽

Harry R. Matthews ◽

Walter A. Patton ◽

...

Keyword(s):

Phospholipase D ◽

Toxin A ◽

Expression Characterization

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Restricted epithelial proliferation by lacritin via PKCα-dependent NFAT and mTOR pathways

The Journal of Cell Biology ◽

10.1083/jcb.200605140 ◽

2006 ◽

Vol 174 (5) ◽

pp. 689-700 ◽

Cited By ~ 36

Author(s):

Jiahu Wang ◽

Ningning Wang ◽

Jinling Xie ◽

Staci C. Walton ◽

Robert L. McKown ◽

...

Keyword(s):

Phospholipase D ◽

Cell Types ◽

Secretory Cells ◽

Dependent Manner ◽

The Novel ◽

Receptor Binding Domain ◽

Epithelial Proliferation ◽

Α Helix ◽

Different Cell Types ◽

Dose Dependent

Renewal of nongermative epithelia is poorly understood. The novel mitogen “lacritin” is apically secreted by several nongermative epithelia. We tested 17 different cell types and discovered that lacritin is preferentially mitogenic or prosecretory for those types that normally contact lacritin during its glandular outward flow. Mitogenesis is dependent on lacritin's C-terminal domain, which can form an α-helix with a hydrophobic face, as per VEGF's and PTHLP's respective dimerization or receptor-binding domain. Lacritin targets downstream NFATC1 and mTOR. The use of inhibitors or siRNA suggests that lacritin mitogenic signaling involves Gαi or Gαo–PKCα-PLC–Ca2+–calcineurin–NFATC1 and Gαi or Gαo–PKCα-PLC–phospholipase D (PLD)–mTOR in a bell-shaped, dose-dependent manner requiring the Ca2+ sensor STIM1, but not TRPC1. This pathway suggests the placement of transiently dephosphorylated and perinuclear Golgi–translocated PKCα upstream of both Ca2+ mobilization and PLD activation in a complex with PLCγ2. Outward flow of lacritin from secretory cells through ducts may generate a proliferative/secretory field as a different unit of cellular renewal in nongermative epithelia where luminal structures predominate.

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Expression, characterization and structural profile of a heterodimeric β-galactosidase from the novel strain Lactobacillus curieae M2011381

Process Biochemistry ◽

10.1016/j.procbio.2020.06.025 ◽

2020 ◽

Vol 97 ◽

pp. 87-95

Author(s):

Jiaying Zhu ◽

Jiaqi Sun ◽

YaJie Tang ◽

Jingli Xie ◽

Dongzhi Wei

Keyword(s):

The Novel ◽

Structural Profile ◽

Expression Characterization

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Novel Lipid-Soluble Thiol-Redox Antioxidant and Heavy Metal Chelator, N,N′-bis(2-Mercaptoethyl)Isophthalamide (NBMI) and Phospholipase D-Specific Inhibitor, 5-Fluoro-2-Indolyl Des-Chlorohalopemide (FIPI) Attenuate Mercury-Induced Lipid Signaling Leading to Protection Against Cytotoxicity in Aortic Endothelial Cells

International Journal of Toxicology ◽

10.1177/1091581811422413 ◽

2011 ◽

Vol 30 (6) ◽

pp. 619-638 ◽

Cited By ~ 9

Author(s):

Jordan D. Secor ◽

Sainath R. Kotha ◽

Travis O. Gurney ◽

Rishi B. Patel ◽

Nicholas R. Kefauver ◽

...

Keyword(s):

Heavy Metal ◽

Phospholipase D ◽

Specific Inhibitor ◽

Lipid Signaling ◽

Dependent Manner ◽

The Novel ◽

Metal Chelator ◽

Thiol Redox ◽

Aortic Endothelial

Here, we investigated thiol-redox-mediated phospholipase D (PLD) signaling as a mechanism of mercury cytotoxicity in mouse aortic endothelial cell (MAEC) in vitro model utilizing the novel lipid-soluble thiol-redox antioxidant and heavy metal chelator, N, N′-bis(2-mercaptoethyl)isophthalamide (NBMI) and the novel PLD-specific inhibitor, 5-fluoro-2-indolyl des-chlorohalopemide (FIPI). Our results demonstrated ( i) mercury in the form of mercury(II) chloride, methylmercury, and thimerosal induced PLD activation in a dose- and time-dependent manner; ( ii) NBMI and FIPI completely attenuated mercury- and oxidant-induced PLD activation; ( iii) mercury induced upstream phosphorylation of extracellular-regulated kinase 1/2 (ERK1/2) leading to downstream threonine phosphorylation of PLD1 which was attenuated by NBMI; ( iv) mercury caused loss of intracellular glutathione which was restored by NBMI; and ( v) NBMI and FIPI attenuated mercury- and oxidant-induced cytotoxicity in MAECs. For the first time, this study demonstrated that redox-dependent and PLD-mediated bioactive lipid signaling was involved in mercury-induced vascular EC cytotoxicity which was protected by NBMI and FIPI.

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