Protein kinase C is involved in 24-hydroxylase gene expression induced by 1,25(OH)2D3 in rat intestinal epithelial cells

1994 ◽  
Vol 55 (2) ◽  
pp. 230-240 ◽  
Author(s):  
Hidenori Koyama ◽  
Masaaki Inaba ◽  
Yoshiki Nishizawa ◽  
Hirotoshi Morii ◽  
Shigeo Ohno
Keyword(s):  
Gene Expression ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Kinase C ◽  
Hydroxylase Gene

scholarly journals Involvement of the ERK Signaling Cascade in Protein Kinase C-mediated Cell Cycle Arrest in Intestinal Epithelial Cells

2003 ◽  
Vol 279 (10) ◽  
pp. 9233-9247 ◽  
Author(s):  
Jennifer A. Clark ◽  
Adrian R. Black ◽  
Olga V. Leontieva ◽  
Mark R. Frey ◽  
Marybeth A. Pysz ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Erk Signaling ◽  
Signaling Cascade ◽  
Intestinal Epithelial ◽  
Cycle Arrest ◽  
Kinase C

scholarly journals Protein kinase C-mediated phosphorylation of RKIP regulates inhibition of Na-alanine cotransport by leukotriene D4in intestinal epithelial cells

2014 ◽  
Vol 307 (11) ◽  
pp. C1010-C1016 ◽  
Author(s):  
Subha Arthur ◽  
Uma Sundaram
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Intracellular Signaling ◽  
Kinase Inhibitor ◽  
Intestinal Epithelial Cells ◽  
Receptor Activation ◽  
Intestinal Epithelial ◽  
Kinase C ◽  
Pka Pathway

Leukotriene D4(LTD4) is an important immune inflammatory mediator that is known to be elevated in the mucosa of chronically inflamed intestine and alter nutrient absorption. LTD4inhibits Na-alanine cotransport in intestinal epithelial cells by decreasing the affinity of the cotransporter ASCT1. LTD4is known to increase intracellular Ca++and cAMP concentrations. However, the intracellular signaling mechanism of LTD4-mediated ASCT1 inhibition is unknown. In the present study, pretreatment with calcium chelator BAPTA-AM or inhibition of Ca++-dependent protein kinase C (PKC), specifically PKCα, resulted in the reversal of LTD4-mediated inhibition of ASCT1, revealing the involvement of the Ca++-activated PKC pathway. PKCα is known to phosphorylate Raf kinase inhibitor protein (RKIP), thus activating its downstream signaling pathway. Immunoblotting with anti-RKIP-Ser153antibody showed an increase in phosphorylation levels of RKIP in LTD4-treated cells. Downregulation of endogenous RKIP showed no decrease in ASCT1 activity by LTD4, thus confirming its involvement in ASCT1 regulation. Phosphorylation of RKIP by PKC is known to activate different signaling pathways, and in this study it was found to activate cAMP-activated protein kinase A (PKA) pathway. Although protein abundance of ASCT1 was not altered in any of the experimental conditions, there was an increase in the levels of phosphothreonine in ASCT1 protein, thus showing that phosphorylation changes were responsible for the altered affinity of ASCT1 by LTD4. In conclusion, LTD4 inhibits ASCT1 through PKC-mediated phosphorylation of RKIP, leading to the subsequent activation of PKA pathway, possibly through β2-andrenergic receptor activation.

Leukotriene D(4) affects localisation of vinculin in intestinal epithelial cells via distinct tyrosine kinase and protein kinase C controlled events

2001 ◽  
Vol 114 (10) ◽  
pp. 1925-1934 ◽  
Author(s):  
R. Massoumi ◽  
A. Sjolander
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Tyrosine Kinase ◽  
Intestinal Epithelial Cells ◽  
Focal Adhesions ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
Kinase C ◽  
E Cadherin

Local inflammatory reactions affect the integrity of intestinal epithelial cells, such as E-cadherin-mediated cell-cell interactions. To elucidate this event, we investigated the effects of an inflammatory mediator, leukotriene D(4)(LTD(4)), on the phosphorylation status and properties of vinculin, a multi-binding protein known to interact with both the E-cadherin-catenin complex and the cytoskeleton. Treatment of an intestinal epithelial cell line with LTD(4)induced rapid tyrosine phosphorylation of vinculin, which was blocked by the Src family tyrosine kinase inhibitor PP1. Simultaneously, LTD(4) caused an increased association between vinculin and actin, and that association was decreased by PP1. LTD(4) also induced dissociation of vinculin from (α)-catenin without affecting the catenin complex itself. This dissociation was not blocked by PP1 but was mimicked by the protein kinase C (PKC) activator 12-O-tetradecanoylphorbol 13-acetate (TPA). Also, the PKC inhibitor GF109203X abolished both the LTD(4)- and the TPA-induced dissociation of vinculin from (α)-catenin. Furthermore, LTD(4) caused a colocalisation of vinculin with PKC-(α) in focal adhesions. This accumulation of vinculin was blocked by transfection with a dominant negative inhibitor of PKC (PKC regulatory domain) and also by preincubation with either GF109203X or PP1. Thus, various LTD(4)-induced phosphorylations of vinculin affect the release of this protein from catenin complexes and its association with actin, two events that are necessary for accumulation of vinculin in focal adhesions. Functionally this LTD(4)-induced redistribution of vinculin was accompanied by a PKC-dependent upregulation of active (β)1 integrins on the cell surface and an enhanced (β)1 integrin-dependent adhesion of the cells to collagen IV.

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