Protein kinase C modulation of queuine uptake in cultured human fibroblasts

A protein of Mr approximately 120,000, related to the human erythrocyte membrane skeletal protein alpha-adducin, has been identified by immunological criteria in human fibroblasts. Using similar methods, beta-adducin (an Mr approximately 110,000 protein that forms a dimeric complex with alpha-adducin in the erythrocyte) is not present in fibroblasts. Subcellular distribution studies reveal that fibroblast alpha-adducin is largely associated with the particulate fraction and is most effectively solubilized from that fraction by a combination of nonionic detergent and high salt. Immunocytochemistry of quiescent fibroblasts shows that alpha-adducin is clustered in large perinuclear arrays that may correspond to vesicular structures; weak staining was also found in the sub-plasma membrane region. As in erythrocytes, the phosphorylation of fibroblast alpha-adducin is elevated on exposure of cells to phorbol esters that activate protein kinase C (PK-C). In addition, various mitogens such as serum, bradykinin and vasopressin also stimulate alpha-adducin phosphorylation by a PK-C-dependent pathway. The elevation in alpha-adducin phosphorylation is maintained for up to 30 min after mitogen addition. Peptide maps of phospho-alpha-adducin from both fibroblasts and erythrocytes after PK-C-mediated phosphorylation showed multiple phosphorylated peptides but with dissimilar migration patterns, suggesting divergence of structure around the phosphorylation sites. Adducin appears to play an important role in the regulation of spectrin-actin interactions in the red cell and may play a role in cytoskeletal function in the fibroblasts.

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Insulin generates free radicals in human fibroblasts ex vivo by a protein kinase C-dependent mechanism, which is inhibited by pravastatin

Free Radical Biology and Medicine ◽

10.1016/j.freeradbiomed.2006.04.015 ◽

2006 ◽

Vol 41 (3) ◽

pp. 473-483 ◽

Cited By ~ 16

Author(s):

G CEOLOTTO ◽

I PAPPARELLA ◽

L LENZINI ◽

M SARTORI ◽

M MAZZONI ◽

...

Keyword(s):

Protein Kinase C ◽

Free Radicals ◽

Protein Kinase ◽

Ex Vivo ◽

Human Fibroblasts ◽

Kinase C ◽

Dependent Mechanism

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High glucose-induced growth factor resistance in human fibroblasts can be reversed by antioxidants and protein kinase C-inhibitors

Cell Biochemistry and Function ◽

10.1002/(sici)1099-0844(199709)15:3<197::aid-cbf740>3.0.co;2-7 ◽

1997 ◽

Vol 15 (3) ◽

pp. 197-201 ◽

Cited By ~ 45

Author(s):

Karin Hehenberger ◽

Anders Hansson

Keyword(s):

Protein Kinase C ◽

Growth Factor ◽

Protein Kinase ◽

High Glucose ◽

Human Fibroblasts ◽

Protein Kinase C Inhibitors ◽

Kinase C

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Post-transcriptional regulation of H-ferritin gene expression in human monocytic THP-1 cells by protein kinase C

Biochemical Journal ◽

10.1042/bj3190185 ◽

1996 ◽

Vol 319 (1) ◽

pp. 185-189 ◽

Cited By ~ 9

Author(s):

Jong-Hwei S. PANG ◽

Chia-Jung WU ◽

Lee-Young CHAU

Keyword(s):

Gene Expression ◽

Protein Synthesis ◽

Protein Kinase C ◽

Protein Kinase ◽

Human Fibroblasts ◽

Leukaemic Cell ◽

Protein Synthesis Inhibitor ◽

Kinase C ◽

Ferritin Gene ◽

The Stability

The mRNA coding for H-ferritin was highly induced in human monocytic THP-1 cells following treatment with phorbol 12-myristate 13-acetate (PMA). The induction was detected at 3 h, reached maximal levels at 12 h, and was sustained for up to 48 h subsequent to PMA exposure. PMA-induced up-regulation of H-ferritin gene expression was also observed in other leukaemic cell lines, HL60 and U937, but not in non-leukaemic cell types, including human fibroblasts, endothelial cells and smooth muscle cells. The effect of PMA could be completely blocked by the protein kinase C inhibitor, H-7. Furthermore, treatment of THP-1 cells with bacterial phospholipase C also produced a marked increase in expression of H-ferritin mRNA, suggesting the activation of protein kinase C was responsible for the accumulation of mRNA. Nuclear run-off experiments demonstrated that PMA did not increase the transcriptional rate of the H-ferritin gene. In contrast, the half-life of the H-ferritin mRNA measured in the presence of actinomycin D was greatly prolonged in PMA-treated cells. The induction of H-ferritin mRNA by PMA required no protein synthesis. Conversely, treatment of THP-1 cells with protein synthesis inhibitor, cycloheximide, resulted in a 4–5-fold increase in H-ferritin mRNA. The increase in the stability of the H-ferritin mRNA was also observed in cells treated with cycloheximide. Taken together, these results suggest that the stability of H-ferritin mRNA in THP-1 is subjected to regulation via a protein kinase C-mediated phosphorylation on existing putative protein factor(s).

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Role of protein kinase C activation in synthesis of complement components C2 and factor B in interferon-γ-stimulated human fibroblasts, glioblastoma cell line A172 and monocytes

Biochemical Journal ◽

10.1042/bj3050425 ◽

1995 ◽

Vol 305 (2) ◽

pp. 425-431 ◽

Cited By ~ 5

Author(s):

I Watanabe ◽

T Horiuchi ◽

S Fujita

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Cell Line ◽

Human Fibroblasts ◽

Cell Types ◽

Glioblastoma Cell Line ◽

Glioblastoma Cell ◽

Ifn Gamma ◽

Factor B ◽

Kinase C

The synthesis of C2 and factor B, the key components of complement system, is performed by various kinds of cells and is also up-regulated by interferon-gamma (IFN-gamma). By using human fibroblasts, human glioblastoma cell line A172 and monocytes, we investigated the signal-transduction mechanism for IFN-gamma-induced synthesis of C2 and factor B. The C2 and factor B synthesis induced by IFN-gamma in all three cell types was inhibited by a protein kinase C (PKC) inhibitor, 1-(5-isoquinolinyl-sulphonyl)-2-methylpiperazine (H-7). The depletion of PKC in these cell types after treatment with phorbol 12-myristate 13-acetate (PMA) resulted in inhibition of IFN-gamma-induced C2 production. In addition, IFN-gamma treatment elicited a decrease in cytoplasmic PKC in A172 cells, indicating that PKC is activated by IFN-gamma. These results suggest that PKC is crucial for IFN-gamma-induced C2 and factor B synthesis. Northern-blot analysis showed that the effects at H-7 were at least partly mediated by modulation of C2 and factor B mRNA abundance in A172 cells. Since treatment of fibroblasts and A172 cells with IFN-gamma had no effect on intracellular Ca2+ concentration, and since neither EGTA nor nifedipine inhibited C2 or factor B synthesis induced by IFN-gamma, we concluded that intracellular Ca2+ mobilization was not involved in the effect of IFN-gamma. In addition, genistein, herbimycin A and N-(6-aminohexyl)-5-chloro-1-naphthalene-sulphonamide (W-7) had no inhibitory effect on IFN-gamma-mediated action in any of the three cell types, which suggests that IFN-gamma acts independently of tyrosine kinases and calmodulin-dependent protein kinases.

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