Translocation of protein kinase C in human polymorphonuclear neutrophils. Regulation by cytosolic Ca2(+)-independent and Ca2(+)-dependent mechanisms.

O’Flaherty, Joseph T.; Jacobson, David P.; Redman, J F; Rossi, Adriano G.

doi:10.1016/s0021-9258(19)38823-4

Cited by 49 publications

(9 citation statements)

References 46 publications

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“…PKC binds to the plasma membrane via the regulatory PKC domain and is inhibited by competitive inhibitors of DAG binding such as sphinganine [12] and dioctanoylglycerol [33]. In the present study, we have analysed the effect of PMN treatment by staurosporine on the kinetic parameters of PDBu-binding sites, which, on the basis of the known specificity of phorbol esters, are assumed to be PKC [5,6,14,25,29]. Results show that staurosporine enhanced both binding capacity and PDBu affinity for PMNs.…”

Section: Discussionmentioning

confidence: 99%

“…The conversion of soluble PKC into its particulate form (translocation) in stimulated cells is considered as a prerequisite for PKC activation by intravesicular DAG. Physiological stimuli promote transient and reversible PKC redistribution, whereas non-physiological stimuli such as phorbol esters induce tight PKC association to the membrane [11,29,31,32]. PKC binds to the plasma membrane via the regulatory PKC domain and is inhibited by competitive inhibitors of DAG binding such as sphinganine [12] and dioctanoylglycerol [33].…”

Section: Discussionmentioning

confidence: 99%

“…Both direct and indirect effects may be involved. Indirect effects may occur through factors known to facilitate PKC translocation, such as DAG and acidic phospholipids [12,36] or Ca2l [27,29]. In human PMNs, the breakdown of phosphatidylcholine through the phospholipase D pathway provides a major source of phosphatidic acid and DAGs [37,38], and treatment of PMNs with staurosporine enhances fMLP-mediated activation [39].…”

Section: Discussionmentioning

confidence: 99%

“…Binding parameter where [29] by incubating them with the Ca2+ chelator Fura 2 and then in the presence of 1 mM EGTA. In these conditions, staurosporine still enhanced both the PDBu-binding affinity and the total binding capacity of PMN, but to a lesser extent than in the presence of Ca2+ (Table 4), suggesting that both Ca2+dependent and -independent mechanisms are involved in the PDBu-binding alterations.…”

Section: Model In Vitro For Translocation Of Pdbu-binding Sites By Staurosporinementioning

confidence: 99%

“…100 nM in resting PMNs [24], was not markedly altered by staurosporine treatment (results not shown), which indicates that the alterations of PDBu binding (Table 4) may be influenced by basal Ca2+ levels. In contrast with staurosporine, chemoattractants, such as N-formyl peptides, induce a translocation of PDBu-binding sites which is transient [29]. To examine whether staurosporine alters the physiological stimulation of the PDBubinding redistribution, PMNs were treated with 100 nM staurosporine and challenged with 100 nM fMLP.…”

Section: Model In Vitro For Translocation Of Pdbu-binding Sites By Staurosporinementioning

confidence: 99%

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A protein kinase inhibitor, staurosporine, enhances the expression of phorbol dibutyrate binding sites in human polymorphonuclear leucocytes

Combadière

Pédruzzi

Hakim

et al. 1993

Biochemical Journal

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Staurosporine, a potent protein kinase C (PKC) inhibitor, was studied for its effects on the binding of phorbol 12,13-dibutyrate (PDBu) to human polymorphonuclear leucocytes (PMNs). Treatment of PMNs with staurosporine concentrations in the range 50 nM-2 microM at 37 degrees C (but not at 4 degrees C) and with 1 nM [3H]PDBu at both temperatures enhanced specific PDBu binding to PMNs by approx. 10-600% relative to control values. The potentiation was rapid (detectable within 1 min) and reached a plateau after 10 min of cell treatment. Scatchard analysis of the binding showed that staurosporine increased the total number of PDBu-binding sites (Bmax) from (178 +/- 9) x 10(3) (control) to (324 +/- 15) x 10(3) sites per PMN and lowered the apparent dissociation constant (Kd) from 9.6 +/- 0.8 (control) to 3.3 +/- 0.3 nM. In Ca(2+)-depleted cells, staurosporine induced similar changes in Kd values, whereas the Bmax. increased by 60%. Treatment of PMNs with 500 nM staurosporine enhanced PDBu binding in the particulate fraction by 120 +/- 7% and decreased PDBu binding in the soluble fraction by 69 +/- 4%, whereas PKC histone-phosphorylating activity of both fractions was almost completely inhibited. Incubation of staurosporine-pretreated particulate fractions with soluble fractions enriched the particulate fraction in PDBu-binding sites at the expense of the soluble fraction, without altering the binding affinity of PDBu for either fraction. Stimulation of PMNs with chemotactic N-formyl peptides induced a transient increase in PDBu binding. This effect was potentiated by approx. 52% by staurosporine. These results show that, in addition to its interference with PKC protein-phosphorylating activity, staurosporine enhances both PDBu-binding capacity and affinity to PMNs, through a mechanism involving Ca(2+)-dependent and -independent processes. Alterations of PDBu binding to soluble and particulate fractions suggest that the enhanced binding capacity in intact PMNs may be due to translocation of PDBu receptors, presumably PKC units. This phenomenon may affect PKC-dependent cellular responses mediated by physiological stimulation.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Model In Vitro For Translocation Of Pdbu-binding Sites By Staurosporinementioning

confidence: 99%

Section: Model In Vitro For Translocation Of Pdbu-binding Sites By Staurosporinementioning

confidence: 99%

See 3 more Smart Citations

A protein kinase inhibitor, staurosporine, enhances the expression of phorbol dibutyrate binding sites in human polymorphonuclear leucocytes

Combadière

Pédruzzi

Hakim

et al. 1993

Biochemical Journal

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Negative and positive regulation of astrocyte DNA synthesis by ethanol

Aroor

Baker

1997

J. Neurosci. Res.

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Ethanol suppression of astrocyte mitogenesis is well recognized but ethanol, under some conditions, has also been shown to stimulate astrocyte proliferation. This study addressed the role of protein kinase C and other mitogenic factors as mechanisms responsible for the bidirectional effects of ethanol on astrocyte DNA synthesis. Ethanol treatment inhibited astrocyte DNA synthesis both at 4 hr (short term) and 24 hr (long term) in serum free medium. In contrast, when the medium contained serum, ethanol was less effective in inhibiting DNA synthesis at 4 hr and treatment with ethanol for 24 hr increased DNA synthesis. Protein kinase C activity was increased in cells treated with ethanol for either 4 or 24 hr. Ethanol inhibition of DNA synthesis in serum free medium was not reversed by down regulating protein kinase C. In contrast, downregulating protein kinase C activity by continuous treatment with phorbol myristic acetate partially reversed the effect ethanol had on DNA synthesis. Also, directly inhibiting protein kinase C with H-7 in cells maintained and treated in the presence of serum abolished the stimulatory effect ethanol had on DNA synthesis. It appears that the negative regulation of astrocyte DNA synthesis by ethanol occurs by protein kinase C and serum independent mechanisms whereas adaptive or stimulatory effects of ethanol on astrocyte DNA synthesis requires the interaction of protein kinase C with other factors present in serum.

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Extracellular ATP-mediated phospholipase a2 activation in rat thyroid FRTL-5 cells: Regulation by a Gi/Go protein, Ca2+, and mitogen-activated protein kinase

et al. 2000

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We investigated the mechanism of phospholipase A(2) (PLA(2)) activation in response to the P2 receptor agonist ATP in rat thyroid FRTL-5 cells. The PLA(2) activity was determined by measuring the release of [(3)H]-arachidonic acid (AA) from prelabeled cells. ATP evoked a dose- and time-dependent AA release. This release was totally inhibited by pertussis toxin (PTX) treatment, indicating the involvement of a G(i)/G(o) protein. The AA release was also diminished by chelating extracellular Ca(2+) with EGTA or by inhibiting influx of Ca(2+) using Ni(2+). Although the activation of protein kinase C (PKC) by 12-phorbol 13-myristate acetate (PMA) alone did not induce any AA release, the ATP-evoked AA release was significantly reduced when PKC was inhibited by GF109203X or by a long incubation with PMA to downregulate PKC. Both the ATP-evoked AA release and the mitogen-activated protein kinase (MAP kinase) phosphorylation were decreased by the MAP kinase kinase (MEK) inhibitor PD98059. Furthermore, the ATP-evoked MAP kinase phosphorylation was also inhibited by GF109203X and by downregulation of PKC, suggesting a PKC-mediated activation of MAP kinase. Inhibiting Src-like kinases by PP1 attenuated both the MAP kinase phosphorylation and the AA release. These results suggest that these kinases are involved in the regulation of MAP kinase and PLA(2) activation. Elevation of intracellular cAMP by TSH or by dBucAMP did not induce a phosphorylation of MAP kinase. Furthermore, neither the ATP-evoked AA release nor the MAP kinase phosphorylation were attenuated by TSH or dBucAMP. Taken together, our results suggest that ATP regulates the activation of PLA(2) by a G(i)/G(o) protein-dependent mechanism. Moreover, Ca(2+), PKC, MAP kinase, and Src-like kinases are also involved in this regulatory process.

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Translocation of protein kinase C in human polymorphonuclear neutrophils. Regulation by cytosolic Ca2(+)-independent and Ca2(+)-dependent mechanisms.

Cited by 49 publications

References 46 publications

A protein kinase inhibitor, staurosporine, enhances the expression of phorbol dibutyrate binding sites in human polymorphonuclear leucocytes

A protein kinase inhibitor, staurosporine, enhances the expression of phorbol dibutyrate binding sites in human polymorphonuclear leucocytes

Negative and positive regulation of astrocyte DNA synthesis by ethanol

Extracellular ATP-mediated phospholipase a2 activation in rat thyroid FRTL-5 cells: Regulation by a Gi/Go protein, Ca2+, and mitogen-activated protein kinase

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