Phospholipase C-protein kinase C mediated phospholipase D activation pathway is involved in tamoxifen induced apoptosis

2003 ◽  
Vol 89 (3) ◽  
pp. 520-528 ◽  
Author(s):  
Soo-Jung Ahn ◽  
Mee-Sup Yoon ◽  
Shin Hyuk ◽  
Wonshik Han ◽  
Yong-Dal Yoon ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Phospholipase D ◽  
C Protein ◽  
Activation Pathway ◽  
Kinase C ◽  
Induced Apoptosis

scholarly journals Targeting of Protein Kinase C-ϵ during Fcγ Receptor-dependent Phagocytosis Requires the ϵC1B Domain and Phospholipase C-γ1

2006 ◽  
Vol 17 (2) ◽  
pp. 799-813 ◽  
Author(s):  
Keylon L. Cheeseman ◽  
Takehiko Ueyama ◽  
Tanya M. Michaud ◽  
Kaori Kashiwagi ◽  
Demin Wang ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Phospholipase D ◽  
Fluorescent Protein ◽  
Wild Type ◽  
Fcγ Receptor ◽  
Kinase C ◽  
Green Fluorescent

Protein kinase C-ϵ (PKC-ϵ) translocates to phagosomes and promotes uptake of IgG-opsonized targets. To identify the regions responsible for this concentration, green fluorescent protein (GFP)-protein kinase C-ϵ mutants were tracked during phagocytosis and in response to exogenous lipids. Deletion of the diacylglycerol (DAG)-binding ϵC1 and ϵC1B domains, or the ϵC1B point mutant ϵC259G, decreased accumulation at phagosomes and membrane translocation in response to exogenous DAG. Quantitation of GFP revealed that ϵC259G, ϵC1, and ϵC1B accumulation at phagosomes was significantly less than that of intact PKC-ϵ. Also, the DAG antagonist 1-hexadecyl-2-acetyl glycerol (EI-150) blocked PKC-ϵ translocation. Thus, DAG binding to ϵC1B is necessary for PKC-ϵ translocation. The role of phospholipase D (PLD), phosphatidylinositol-specific phospholipase C (PI-PLC)-γ1, and PI-PLC-γ2 in PKC-ϵ accumulation was assessed. Although GFP-PLD2 localized to phagosomes and enhanced phagocytosis, PLD inhibition did not alter target ingestion or PKC-ϵ localization. In contrast, the PI-PLC inhibitor U73122 decreased both phagocytosis and PKC-ϵ accumulation. Although expression of PI-PLC-γ2 is higher than that of PI-PLC-γ1, PI-PLC-γ1 but not PI-PLC-γ2 consistently concentrated at phagosomes. Macrophages from PI-PLC-γ2-/-mice were similar to wild-type macrophages in their rate and extent of phagocytosis, their accumulation of PKC-ϵ at the phagosome, and their sensitivity to U73122. This implicates PI-PLC-γ1 as the enzyme that supports PKC-ϵ localization and phagocytosis. That PI-PLC-γ1 was transiently tyrosine phosphorylated in nascent phagosomes is consistent with this conclusion. Together, these results support a model in which PI-PLC-γ1 provides DAG that binds to ϵC1B, facilitating PKC-ϵ localization to phagosomes for efficient IgG-mediated phagocytosis.

Leptin Constrains Phospholipase C-Protein Kinase C-Induced Insulin Secretion via a Phosphatidylinositol 3-Kinase-Dependent Pathway

2003 ◽  
Vol 228 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Joo-Won Lee ◽  
Andrew G. Swick ◽  
Dale R. Romsos
Keyword(s):  
Protein Kinase C ◽  
Insulin Secretion ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Phosphatidylinositol 3 Kinase ◽  
C Protein ◽  
Kinase C ◽  
Pka Pathway ◽  
Stimulation Of ◽  
Phosphatidylinositol 3

Leptin-deficient Lepob/Lepob mice hypersecrete insulin in response to acetylcholine stimulation of the phospholipase C-protein kinase C (PLC-PKC) pathway, and leptin constrains this hypersecretion. Leptin has been reported to activate phosphatidylinositol 3-kinase (PI 3-K) and subsequently phosphodiesterase (PDE) to impair protein kinase A (PKA)-induced insulin secretion from cultured islets of neonatal rats. We determined if PKA-induced insulin secretion was also hyperresponsive in Islets from Lepob/Lepob mice, and if leptin impaired this pathway in islets from these mice. Additionally, the possible role for PI 3-K and PDE in leptin-induced control of acetylcholine-induced insulin secretion was examined. Stimulation of Insulin secretion with GLP-1, forskolin (an activator of adenylyl cyclase), or IBMX (an inhibitor of PDE) did not cause hypersecretion of insulin from islets of young Lepob/Lepob mice, and leptin did not inhibit GLP-1-induced insulin secretion from islets of these mice. Inhibition of PDE with IBMX also did not block leptin-induced inhibition of acetylcholine-mediated insulin secretion from islets of Lepob/Lepob mice. But, preincubation of islets with wortmannin, an Inhibitor of PI 3-K activity, blocked the ability of leptin to constrain acetylcholine-induced insulin secretion from islets of Lepob/Lepob mice. We conclude that the capacity of the PKA pathway to stimulate insulin secretion is not increased in islets from young Lepob/Lepob mice, and that leptin does not regulate this pathway in islets from mice. Leptin may stimulate PI 3-K to constrain PLC-PKC-induced insulin secretion from Islets of Lepob/Lepob mice.

Assembly and sealing of tight junctions: Possible participation of G-proteins, phospholipase C, protein kinase C and calmodulin

1991 ◽  
Vol 122 (3) ◽  
pp. 193-202 ◽  
Author(s):  
M. S. Balda ◽  
L. González-Mariscal ◽  
R. G. Contreras ◽  
M. Macias-Silva ◽  
M. E. Torres-Marquez ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Tight Junctions ◽  
G Proteins ◽  
C Protein ◽  
Kinase C

Leishmania amazonensis: Heme stimulates (Na++K+)ATPase activity via phosphatidylinositol-specific phospholipase C/protein kinase C-like (PI-PLC/PKC) signaling pathways

2010 ◽  
Vol 124 (4) ◽  
pp. 436-441 ◽  
Author(s):  
Elmo Eduardo Almeida-Amaral ◽  
Viviane Carrozino Cardoso ◽  
Fernanda Gomes Francioli ◽  
José Roberto Meyer-Fernandes
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Atpase Activity ◽  
Signaling Pathways ◽  
Phospholipase C ◽  
Leishmania Amazonensis ◽  
C Protein ◽  
Kinase C ◽  
Pkc Signaling
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