Phosphatase inhibitors suppress Ca2+ influx induced by receptor-mediated intracellular Ca2+ store depletion in human platelets

Koike, Yukihiro; Yukio, Ozaki; Qi, Robert Z.; Satoh, Kaneo; Kurota, Kenji; Yatomi, Yutaka; Kudoh, Shoji

doi:10.1016/0143-4160(94)90013-2

Cited by 34 publications

(20 citation statements)

References 36 publications

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“…due to PP1 binding, as appears to be the case with cantharidin and its derivatives (43)). Tautomycin has similar affinities for PP1 and PP2A (44) but seems to have calyculin-like effects in intact cells (45). The plectin phosphorylation and network disruption induced by calyculin A, cantharidin, and tautomycin could, therefore, reflect the engagement of PP1 as well as PP2A in plectin dephosphorylation.…”

Section: Table III Protective Effects Of Protein Kinase Inhibitors Agmentioning

confidence: 99%

“…It is therefore conceivable that inhibition of PP1 by calyculin A or cantharidin induces a naringin-resistant plectin phosphorylation that overrides the naringin-sensitive, PP2A-regulated phosphorylation. Tautomycin inhibits purified PP1 and PP2A with equal potency (44) but has been reported to act more like calyculin A than like okadaic acid in intact cells (45).…”

Section: Table Imentioning

confidence: 99%

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Naringin-sensitive Phosphorylation of Plectin, a Cytoskeletal Cross-linking Protein, in Isolated Rat Hepatocytes

Larsen¹,

Møller²,

Blankson

et al. 2002

Journal of Biological Chemistry

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To identify phosphoproteins that might play a role in naringin-sensitive hepatocellular cytoskeletal disruption and apoptosis induced by algal toxins, hepatocyte extracts were separated by gel electrophoresis and immunostained with a phosphothreonine-directed antibody. Use of dilute (5%) polyacrylamide gels containing 6 M urea allowed the resolution of one very large (ϳ500-kDa) okadaic acid-and naringin-sensitive phosphoprotein, identified by tryptic fingerprinting, matrixassisted laser desorption/ionization time-of-flight mass spectrometry, and immunostaining as the cytolinker protein, plectin. The naringin-sensitive phosphorylation induced by okadaic acid and microcystin-LR probably reflected inhibition of a type 2A protein phosphatase, whereas the naringin-resistant phosphorylation induced by calyculin A, tautomycin, and cantharidin probably involved a type 1 phosphatase. Okadaic acid caused a collapse of the plectin-immunostaining bile canalicular sheaths and the general cytoskeletal plectin network into numerous medium-sized plectin aggregates. Inhibitors of protein kinase C, cAMP-dependent protein kinase, or Ca 2؉ /calmodulin-dependent kinase II had moderate or no protective effects on plectin network disruption, whereas naringin offered 86% protection. Okadaic acid induced a naringin-sensitive phosphorylation of AMP-activated protein kinase (AMPK), the stress-activated protein kinases SEK1 and JNK, and S6 kinase. The AMPK-activating kinase (AMPKK) is likely to be the target of inhibition by naringin, the other kinases serving as downstream components of an AMPKK-initiated signaling pathway.

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Section: Table III Protective Effects Of Protein Kinase Inhibitors Agmentioning

confidence: 99%

Section: Table Imentioning

confidence: 99%

Naringin-sensitive Phosphorylation of Plectin, a Cytoskeletal Cross-linking Protein, in Isolated Rat Hepatocytes

Larsen¹,

Møller²,

Blankson

et al. 2002

Journal of Biological Chemistry

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“…The suppression of Ca2+ entry by serine/threonine phosphatase inhibitors has also been described in human platelets (34), HeLa cells (35) and human neutrophils (36). Therefore, it seems that modulation of the capacitative Ca 2+ entry through phosphorylation/dephosphorylation is a widespread mechanism present in many cell types.…”

Section: Discussionmentioning

confidence: 99%

Suppression of Capacitative Ca2+ Entry by Serine/Threonine Phosphatase Inhibitors in Rat Parotid Acinar Cells

Tojyo

Tanimura

Matsumoto

1995

Japanese Journal of Pharmacology

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ABSTRACT-The effects of three serine/threonine protein phosphatase inhibitors, calyculin-A, tautomycin and okadaic acid, on the Ca" entry across the plasma membrane was studied in Fura-2-loaded rat parotid acinar cells. These protein phosphatase inhibitors did not affect the peak elevation of cytosolic free Ca 21 concentration ([Ca 211,) just after stimulation with the muscarinic agonist carbachol (CCh), but they suppressed the sustained increase in [Ca 2+]i. In the absence of extracellular Ca2+, CCh produced a transient increase in [Ca 2+]; due to Ca2+ release from intracellular Ca2+ stores, and this increase in [Ca 2+], was unaffected by the phosphatase inhibitors. When Ca 2+ was added to the external medium after the transient [Ca 2+]i response, the increase in [Ca 2+]i in the cells treated with the phosphatase inhibitors was significantly smaller than that in the control cells, indicating that the Ca 2+ entry was reduced. Similar suppression of Ca 2+ entry by the phosphatase inhibitors was observed when intracellular Ca 2+ stores were previously depleted by the microsomal Ca 2+-ATPase inhibitor thapsigargin (TG). In addition, the phosphatase inhibitors reduced the Mn2+ (Ca 2+ surrogate) influx following the addition of CCh or TG. The enhancement of Ca 2+ entry by the protein kinase inhibitor staurosporine was significantly attenuated by the phosphatase inhibitors. These results suggest that the phosphatase inhibitors suppressed the Ca 2+ entry mechanism activated by depletion of intracellular Ca 2+ stores in rat parotid acinar cells. The capacitative Ca 2+ entry may be regulated by protein phosphorylation/dephosphorylation.

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“…Communication between depleted Ca25 pools and plasma membranes has been the focus of several studies, but the mechanism responsible for the communication still remains obscure. A diffusible Ca25 influx factor (Randriamampita and Tsien, 1993), small molecular weight G proteins (Bird and Putney, 1994), and phosphatases (Koike et a!., 1994) son et al (1993) reported that Ca 25 mobilization after internal Ca25 depletion in pancreatic acinar cells is modulated by cGMP. Their finding implied a link between Ca25 mobilization and cGMP; therefore, we set out to identify the factor(s) capable of inducing guanylate cyclase activation and consequently increasing [cGMP]~.…”

Section: No Diffusibilitymentioning

confidence: 99%

“…The nature of the capacitative Ca2~entry is not completely understood. Factors that are believed to modulate capacitative Ca2~entry include small molecular weight G proteins (Bird and Putney, 1994), serine/threonine phosphatases (Koike et al, 1994), tyrosine kinase or phosphatase (Bischof et al, 1995a), cyclic AMP (Denning et al, 1994), and nitric oxide (NO) and cyclic GMP (cGMP) (Gukovskaya and Pandol, 1994;Xu et al, 1994). Through its activation of soluble guanylate cyclase, the releasing factor NO is known to play a very important role in several physiological functions (Fostermann et al, 1993).…”

mentioning

confidence: 99%

Arginine‐Modulated Receptor‐Activated Calcium Influx via a NO/Cyclic GMP Pathway in Human SK‐N‐SH Neuroblastoma Cells

Liu

Shaw

1997

Journal of Neurochemistry

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Abstract:The effects of arginine on calcium mobilization in human SK-N-SH neuroblastoma cells were examined. It was found that arginine potentiated an increase in carbachol-induced Ca 2~from the external Ca2~influx as opposed to an internal Ca2~release from intracellular pools. The potentiation effect of arginine on carbacholinduced calcium mobilization was mimicked by either 8-bromo cyclic GMP or sodium nitroprusside. In addition, it was found that arginine induced NO production and an increase in cyclic GMP. Moreover, arginine-induced potentiation, NO production, and cyclic GMP increases were all suppressed after the preincubation of cells with N-methyl-L-arginine or N-nitro-L-arginine, nitric oxide synthase inhibitor. It is suggested that the NO production and subsequent cyclic GMP elevation induced by arginine are responsible for the potentiation of carbacholinduced Ca2~increase. Our results show the existence of a NO/cyclic GMP pathway and an interconnection of NO and Ca2signaling pathways in human SK-N-SH neuroblastoma cells. We also observed that NO, which is produced by endothelial CPAE cells, has a modulating effect on cyclic GMP elevation in human SK-N-SH neuroblastoma cells. The intercellular communication role of NO and its cell-diffusing character may also affect the regulation of nonneuronal cells in their interactions with neuronal cells.

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Phosphatase inhibitors suppress Ca2+ influx induced by receptor-mediated intracellular Ca2+ store depletion in human platelets

Cited by 34 publications

References 36 publications

Naringin-sensitive Phosphorylation of Plectin, a Cytoskeletal Cross-linking Protein, in Isolated Rat Hepatocytes

Naringin-sensitive Phosphorylation of Plectin, a Cytoskeletal Cross-linking Protein, in Isolated Rat Hepatocytes

Suppression of Capacitative Ca2+ Entry by Serine/Threonine Phosphatase Inhibitors in Rat Parotid Acinar Cells

Arginine‐Modulated Receptor‐Activated Calcium Influx via a NO/Cyclic GMP Pathway in Human SK‐N‐SH Neuroblastoma Cells

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