scholarly journals Changes in protein kinase C ∊ phosphorylation status and intracellular localization as 3T3 and 3T6 fibroblasts grow to confluency and quiescence: a role for phosphorylation at Ser-729?

2000 ◽  
Vol 352 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Karen ENGLAND ◽  
Martin G. RUMSBY
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Intracellular Localization ◽  
C6 Glioma Cells ◽  
Nuclear Fraction ◽  
Cell Fractionation ◽  
Cytosol Fraction ◽  
Kinase C ◽  
Sds Page ◽  
Molecular Masses

Protein kinase C (PKC) ε in 3T3 and 3T6 fibroblasts and in C6 glioma cells migrated on SDS/PAGE predominantly as a doublet with molecular masses of 87 and 95kDa (PKC ε87 and PKC ε95 respectively). PKC ε95 predominates when cells reach confluency but PKC ε87 was the main form detected within 15min when confluent cells were passaged at low cell density into fresh medium containing serum and allowed to adhere. Matrix-assisted laser-desorption ionization–time-of-flight MS analysis and experiments with phosphospecific antibodies revealed that PKC ε87 is phosphorylated at Thr-566 and Ser-703, and PKC ε95 is additionally phosphorylated at Ser-729. Cell fractionation studies revealed that PKC ε95 is associated with the nuclear fraction, whereas PKC ε87 was found in the 100000g cytosol fraction. Immunofluorescence studies confirmed these findings and showed that PKC ε95 had a perinuclear, probably Golgi, localization and PKC ε87 was distributed in the cytosol. It is proposed that phosphorylation at Ser-729 may be important for determining the intracellular localization of PKC ε, and that a specific Ser-729 phosphatase may be activated on cell passage to convert PKC ε95 to PKC ε87.

scholarly journals Dysregulation of protein kinase C in adult depression and suicide: evidence from postmortem brain studies

2021 ◽  
Author(s):  
Ghanshyam N Pandey ◽  
Anuradha Sharma ◽  
Hooriyah S Rizavi ◽  
Xinguo Ren
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Expression ◽  
Mrna Expression ◽  
Postmortem Brain ◽  
Cortical Region ◽  
Cytosol Fraction ◽  
Kinase C ◽  
Pkc Isozymes

Abstract Background Several lines of evidence suggest the abnormalities of protein kinase C (PKC) signaling system in mood disorders and suicide based primarily on the studies of PKC and its isozymes in the platelets and postmortem brain of depressed and suicidal subjects. In this study we examined the role of PKC isozymes in depression and suicide. Methods We determined the protein and mRNA expression of various PKC isozymes in the prefrontal cortical region [Brodmann area 9 (BA9)] in 24 normal control (NC) subjects, 24 depressed suicide (DS) subjects and 12 depressed non-suicide (DNS) subjects. The levels of mRNA in the prefrontal cortex (PFC) were determined by qRT-PCR and the protein expression was determined by Western blotting. Results We observed a significant decrease in mRNA expression of PKCα, PKCβI, PKCδ and PKCε and decreased protein expression either in the membrane or the cytosol fraction of PKC isozymes - PKCα, PKCβI, PKCβII and PKCδ in DS and DNS subjects compared with NC subjects. Conclusions The current study provides detailed evidence of specific dysregulation of certain PKC isozymes in the postmortem brain of DS and DNS subjects and further supports earlier evidence for the role of PKC in the platelets and brain of adult and teenage depressed and suicidal population. This comprehensive study may lead to further knowledge of the involvement of PKC in the pathophysiology of depression and suicide.

scholarly journals Identification of phosphatidylserine-binding proteins in human white blood cells

1990 ◽  
Vol 269 (3) ◽  
pp. 723-728 ◽  
Author(s):  
M Wolf ◽  
M Baggiolini
Keyword(s):  
Protein Kinase C ◽  
Blood Cells ◽  
Binding Proteins ◽  
White Blood Cells ◽  
Human Neutrophils ◽  
Kinase C ◽  
Sds Page ◽  
Molecular Masses ◽  
Human White Blood Cells ◽  
Monocytes And Lymphocytes

Cytosol and membrane fractions from human neutrophils, monocytes, lymphocytes and platelets were separated by SDS/PAGE, blotted on to nitrocellulose and assayed for selective binding of phosphatidylserine (PS). Two PS-binding proteins with apparent molecular masses of 115 kDa and 100 kDa were identified in the cytosol of neutrophils, monocytes and lymphocytes. Corresponding bands along with other PS-binding proteins were detected in platelets in both cytosol and membrane fractions. These proteins were also found to bind protein kinase C (PKC) provided that PS was present. The 115 kDa and 100 kDa proteins (PS-p115/110) were partially purified from neutrophils and were used for the study of PS and PKC binding. The binding of PS did not require Ca2+ or Mg2+ and was inhibited by phosphatidic acid, by 1-alkyl-2-acetylphosphocholine and, to a lesser extent, by other lipids. The binding of PKC, however, was strictly PS- and Ca2(+)-dependent and seems to occur secondarily to PS binding.

The role of protein kinase C-δ in PTH stimulation of IGF-binding protein-5 mRNA in UMR-106–01 cells

2002 ◽  
Vol 282 (3) ◽  
pp. E534-E541 ◽  
Author(s):  
Mary S. Erclik ◽  
Jane Mitchell
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Binding Protein ◽  
Specific Inhibitor ◽  
Dominant Negative Mutant ◽  
Nuclear Fraction ◽  
Mrna Levels ◽  
Kinase C ◽  
Umr 106

We have investigated the role of protein kinase C (PKC) signal transduction pathways in parathyroid hormone (PTH) regulation of insulin-like growth factor-binding protein-5 (IGFBP-5) gene expression in the rat osteoblast-like cell line UMR-106–01. Involvement of the PKC pathway was determined by the findings that bisindolylmaleimide I inhibited 40% of the PTH effect, and 1 μM bovine PTH-(3–34) stimulated a 10-fold induction of IGFBP-5 mRNA. PTH-(1–34) and PTH-(3–34) (100 nM) both stimulated PKC-δ translocation from the membrane to the nuclear fraction. Rottlerin, a PKC-δ-specific inhibitor, and a dominant negative mutant of PKC-δ were both able to significantly inhibit PTH-(1–34) and PTH-(3–34) induction of IGFBP-5 mRNA, suggesting a stimulatory role for PKC-δ in the effects of PTH. Phorbol 12-myristate 13-acetate (PMA) stimulated PKC-α translocation from the cytosol to the membrane and inhibited ∼50% of the PTH-(1–34), forskolin, and 8-bromoadenosine 3′,5′-cyclic monophosphate-stimulated IGFBP-5 mRNA levels, suggesting that PKC-α negatively regulates protein kinase A (PKA)-mediated induction of IGFBP-5 mRNA. These results suggest that the induction of IGFBP-5 by PTH is both PKA and PKC dependent and PKC-δ is the primary mediator of the effects of PTH via the PKC pathway.

scholarly journals Protein kinase C-β contributes to NADPH oxidase activation in neutrophils

2000 ◽  
Vol 347 (1) ◽  
pp. 285-289 ◽  
Author(s):  
Lodewijk V. DEKKER ◽  
Michael LEITGES ◽  
Gabriel ALTSCHULER ◽  
Nishil MISTRY ◽  
Aileen MCDERMOTT ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Nadph Oxidase ◽  
Specific Inhibitor ◽  
Human Neutrophils ◽  
Cell Fractionation ◽  
Coated Particles ◽  
Kinase C ◽  
Pkc Β ◽  
Nadph Oxidase Activation

We have analysed the involvement of the β isotype of the protein kinase C (PKC) family in the activation of NADPH oxidase in primary neutrophils. Using immunofluorescence and cell fractionation, PKC-β is shown to be recruited to the plasma membrane upon stimulation with phorbol ester and to the phagosomal membrane upon phagocytosis of IgG-coated particles (Fcγ-receptor stimulus). The time course of recruitment is similar to that of NADPH oxidase activation by these stimuli. The PKC-β specific inhibitor 379196 inhibits the response to PMA as well as to IgG-coated bacteria. Partial inhibition occurs between 10 and 100 nM of inhibitor, the concentration at which PKC-β, but not other PKC isotypes, is targeted. Neutrophils isolated from a mouse that lacks PKC-β also showed an inhibition of NADPH oxidase activation by PMA and IgG-coated particles. The level of inhibition is comparable to that achieved with 379196 in human neutrophils. Thus the PKC-β isotype mediates activation of NADPH oxidase by PMA and by stimulation of Fcγ receptors in neutrophils.

scholarly journals 2adrenoreceptor agonist regulates protein kinase C-induced heat shock protein 27 phosphorylation in C6 glioma cells

2008 ◽  
Vol 106 (2) ◽  
pp. 519-528 ◽  
Author(s):  
Kumiko Tanabe ◽  
Shinji Takai ◽  
Rie Matsushima-Nishiwaki ◽  
Kanefusa Kato ◽  
Shuji Dohi ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Heat Shock ◽  
Protein Kinase ◽  
Heat Shock Protein ◽  
Glioma Cells ◽  
Heat Shock Protein 27 ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
Kinase C

scholarly journals Pinus densiflora Gnarl Inhibits Migration through Suppression of Protein Kinase C in C6 Glioma Cells

2015 ◽  
Vol 32 (2) ◽  
pp. 51-58
Author(s):  
Ilguk Min ◽  
Kangpa Lee ◽  
Haeryong Chang ◽  
Jinyoung Moon
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Pinus Densiflora ◽  
Glioma Cells ◽  
C6 Glioma ◽  
C6 Glioma Cells ◽  
Kinase C

scholarly journals Purification and characterization of protein kinase C from the nematode Caenorhabditis elegans

1992 ◽  
Vol 282 (1) ◽  
pp. 219-223 ◽  
Author(s):  
T Sassa ◽  
J Miwa
Keyword(s):  
Protein Kinase C ◽  
Caenorhabditis Elegans ◽  
Protein Kinase ◽  
Column Chromatography ◽  
Purification And Characterization ◽  
C Elegans ◽  
Kinase C ◽  
Sds Page ◽  
Cytosolic Extract

Protein kinase C (PKC) of Caenorhabditis elegans was identified by enzymatic activity and [3H]phorbol 12,13-dibutyrate binding after DEAE-Sephacel column chromatography of a crude cytosolic extract. Ca(2+)-dependent activation of nematode PKC was observed in the presence of phosphatidylserine. The enzyme was maximally activated by 1,2-dioleoylglycerol or phorbol 12-myristate 13-acetate in the presence of phosphatidylserine and Ca2+. Hydroxyapatite column chromatography showed only one peak of PKC activity with histone H1 and myelin basic protein as substrates. The enzyme was purified to near homogeneity by sequential chromatography on polylysine-agarose and phosphatidylserine affinity columns. The purified protein showed a molecular mass of 79 kDa on SDS/PAGE. The substrate specificity of the C. elegans enzyme was shown to be different from that of mammalian PKCs. Here we describe some of the properties of the nematode enzyme.

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