Phosphorylation of myristoylated alanine-rich C kinase substrate is involved in the cAMP-dependent amylase release in parotid acinar cells

2009 ◽  
Vol 296 (6) ◽  
pp. G1382-G1390 ◽  
Author(s):  
Keitaro Satoh ◽  
Miwako Matsuki-Fukushima ◽  
Bing Qi ◽  
Ming-Yu Guo ◽  
Takanori Narita ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Acinar Cells ◽  
Cellular Migration ◽  
Intracellular Camp ◽  
Dependent Manner ◽  
Amylase Release ◽  
Kinase Substrate ◽  
Parotid Acinar Cells ◽  
Dependent Protein ◽  
Rat Parotid

Myristoylated alanine-rich C kinase substrate (MARCKS) is known as a major cellular substrate for protein kinase C (PKC). MARCKS has been implicated in the regulation of brain development and postnatal survival, cellular migration and adhesion, as well as phagocytosis, endocytosis, and exocytosis. The involvement of MARCKS phosphorylation in secretory function has been reported in Ca2+-mediated exocytosis. In rat parotid acinar cells, the activation of β-adrenergic receptors provokes exocytotic amylase release via accumulation of intracellular cAMP levels. Here, we studied the involvement of MARCKS phosphorylation in the cAMP-dependent amylase release in rat parotid acinar cells. MARCKS protein was detected in rat parotid acinar cells by Western blotting. The β-adrenergic agonist isoproterenol (IPR) induced MARCKS phosphorylation in a time-dependent manner. Translocation of a part of phosphorylated MARCKS from the membrane to the cytosol and enhancement of MARCKS phosphorylation at the apical membrane site induced by IPR were observed by immunohistochemistry. H89, a cAMP-dependent protein kinase (PKA) inhibitor, inhibited the IPR-induced MARCKS phosphorylation. The PKCδ inhibitor rottlerin inhibited the IPR-induced MARCKS phosphorylation and amylase release. IPR activated PKCδ, and the effects of IPR were inhibited by the PKA inhibitors. A MARCKS-related peptide partially inhibited the IPR-induced amylase release. These findings suggest that MARCKS phosphorylation via the activation of PKCδ, which is downstream of PKA activation, is involved in the cAMP-dependent amylase release in parotid acinar cells.

scholarly journals Two modes of regulation of the phospholipase C-linked substance-P receptor in rat parotid acinar cells

1988 ◽  
Vol 253 (2) ◽  
pp. 459-466 ◽  
Author(s):  
H Sugiya ◽  
J F Obie ◽  
J W Putney
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Substance P ◽  
Acinar Cells ◽  
Control Mechanisms ◽  
Dependent Manner ◽  
Parotid Acinar Cells ◽  
Kinase C ◽  
Substance P Receptor ◽  
Rat Parotid

In rat parotid acinar cells prelabelled with [3H]inositol, substance P (100 nM) induced the formation of [3H]inositol 1,4,5-trisphosphate [Ins(1,4,5)P3]. Ins(1,4,5)P3 reached a maximum 7 s after substance P stimulation, and thereafter decreased and reached a stable value at 60 s. When the cells were exposed to substance P for 10, 30, 60, or 300 s, washed, and re-exposed to this peptide, the formation of [3H]inositol trisphosphate (InsP3) was attenuated in a time-dependent manner. In the cells pretreated as described above, the number of [3H]substance-P-binding sites (Bmax) was also decreased. Possible role(s) of Ca2+ and protein kinase (protein kinase C) control mechanisms in regulating substance P responses were investigated. Desensitization of substance P-induced InsP3 was not affected by the Ca2+ ionophore ionomycin, nor was it dependent on Ca2+ mobilization. On the other hand, in the presence of 4 beta-phorbol 12,13-dibutyrate (PDBu) and 12-O-tetradecanoyl-4 beta-phorbol 13-acetate, known activators of protein kinase C, substance P-induced InsP3 formation was inhibited. However, PDBu had no effect on [3H]substance P binding, whether present during the assay or when cells were pretreated. The persistent desensitization of InsP3 formation induced by substance P was not affected by PDBu. These results suggest that the persistent desensitization of InsP3 formation induced by substance P is a homologous process involving down-regulation of the substance P receptor; the mechanism does not appear to involve, or to be affected by, the Ca2+ or protein kinase C signalling systems. Protein kinase C activation can, however, inhibit substance P-induced InsP3 formation, which may indicate the presence of a negative-feedback control on the substance P pathway.

scholarly journals Role of protein kinase C-δ in isoproterenol-induced amylase release in rat parotid acinar cells

2009 ◽  
Vol 56 (Supplement) ◽  
pp. 368-370 ◽  
Author(s):  
Hiroshi Sugiya ◽  
Keitaro Satoh ◽  
Miwako Matsuki-Fukushima ◽  
Bing Qi ◽  
Ming-Yu Guo ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Acinar Cells ◽  
Amylase Release ◽  
Parotid Acinar Cells ◽  
Kinase C ◽  
Rat Parotid

Exocyst subunits are involved in isoproterenol-induced amylase release from rat parotid acinar cells

2012 ◽  
Vol 120 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Akane Imai ◽  
Sumio Yoshie ◽  
Maiko Haga-Tsujimura ◽  
Tomoko Nashida ◽  
Hiromi Shimomura
Keyword(s):  
Acinar Cells ◽  
Amylase Release ◽  
Parotid Acinar Cells ◽  
Rat Parotid

scholarly journals Regulation of ERK1/2 by ouabain and Na-K-ATPase-dependent energy utilization and AMPK activation in parotid acinar cells

2008 ◽  
Vol 295 (3) ◽  
pp. C590-C599 ◽  
Author(s):  
Stephen P. Soltoff ◽  
Lee Hedden
Keyword(s):  
Protein Kinase ◽  
Muscarinic Receptor ◽  
Growth Factor Receptor ◽  
Acinar Cells ◽  
Receptor Activation ◽  
Energy Utilization ◽  
Ampk Activation ◽  
Parotid Acinar Cells ◽  
Ampk Phosphorylation ◽  
Rat Parotid

We previously found that the phosphorylation of ERK1/2 by submaximal concentrations of the muscarinic receptor ligand carbachol was potentiated in rat parotid acinar cells exposed to ouabain, a cardiac glycoside that inhibits the Na-K-ATPase. We now report that this signaling phenomenon involves the prevention of negative regulation of extracellular signal-regulated kinase-1/2 (ERK1/2) that is normally mediated by AMP-activated protein kinase (AMPK). Carbachol increases the turnover of the ATP-consuming Na-K-ATPase, reducing intracellular ATP and promoting the phosphorylation/activation of the energy sensor AMPK. Ouabain blocks the reduction in ATP and subsequent AMPK phosphorylation, which is regulated by the AMP-to-ATP ratio. The ouabain-promoted enhancement of ERK1/2 phosphorylation was not reproduced in Par-C10 cells, an immortalized rat parotid cell line that did not respond to carbachol with an ATP reduction and that employs an upstream AMPK kinase (Ca2+/calmodulin-dependent protein kinase kinase, CaMKK) different from that (LKB1) in native cells. In native parotid cells, inhibitory effects of AMPK on ERK1/2 signaling were examined by activating AMPK with 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR), which is converted to an AMP mimetic but does not alter parotid ATP levels. AICAR-treated cells display increases in AMPK phosphorylation and a reduced phosphorylation of ERK1/2 subsequent to activation of muscarinic and P2X7 receptors, which promote increases in Na-K-ATPase turnover, but not upon epidermal growth factor receptor activation. These results suggest that carbachol-initiated AMPK activation can produce a negative feedback on ERK1/2 signaling in response to submaximal muscarinic receptor activation and that increases in fluid secretion can modulate receptor-initiated signaling events indirectly by producing ion transport-dependent decreases in ATP.

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