Inhibitors of protein kinase C (PKC) prevent activated transcription: role of events downstream of NF-kappaB DNA binding

Catley, Matthew C. and Cambridge, Lisa M. and Nasuhara, Yasuyuki and Ito, Kazuhiro and Chivers, Joanna E and Beaton, Andrew and Holden, Neil S. and Bergmann, Martin W. and Barnes, Peter J. and Newton, Robert (2004) Inhibitors of protein kinase C (PKC) prevent activated transcription: role of events downstream of NF-kappaB DNA binding. Journal of Biological Chemistry, 279 (18). pp. 18457-18466. ISSN 0021-9258

Full content URL: http://dx.doi.org/10.1074/jbc.M400765200

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Item Type:Article
Item Status:Live Archive

Abstract

In pulmonary A549 cells, the protein kinase C (PKC) inhibitor, Ro 31-8220, and the phosphotidylcholine-specific phospholipase C inhibitor, D609, prevent NF-kappaB-dependent transcription, yet NF-kappaB DNA binding is unaffected (Bergmann, M., Hart, L., Lindsay, M., Barnes, P. J., and Newton, R. (1998) J. Biol. Chem. 273, 6607-6610). We now show that this effect also occurs in BEAS-2B bronchial epithelial cells as well as with other PKC inhibitors (Gö 6976, GF109203X, and calphostin C) in A549 cells. Similarly, phorbol ester, a diacylglycerol mimetic, activates NF-kappaB-dependent transcription and potentiates tumor necrosis factor alpha (TNFalpha)-induced NF-kappaB-dependent transcription, yet unlike TNFalpha, poorly activates IkappaB kinase (IKK) activity, IkappaBalpha degradation, or NF-kappaB DNA binding in both A549 and BEAS-2B cells. As phorbol ester-induced NF-kappaB-dependent transcription was relatively insensitive to the proteasome inhibitor, MG-132, PKC may affect NF-kappaB-dependent transcription via mechanisms other than the core IKK-IkappaB pathway. This is supported by Gal4 one hybrid analysis of p65/RelA transactivation, which was potentiated by TNFalpha and phorbol ester and was inhibited by Ro 31-8220 and D609. Additionally, a number of PKC isoforms, particularly the novel isoform PKCepsilon, induced p65/RelA transactivation. Phosphorylation of p65/RelA and cAMP-responsive element-binding protein (CREB)-binding protein (CBP) was increased by TNFalpha treatment and, in the case of CBP, was prevented by Ro 31-8220 or D609. However, p65/RelA-CBP interactions were unaffected by either compound. As this effect was not limited to NF-kappaB, but was a more general feature of inducible gene transcription, we suggest PKC isoforms may provide a point of intervention in diseases such as inflammation, or cancer, where activated gene expression is prominent.

Keywords:Protein kinase
Subjects:C Biological Sciences > C720 Biological Chemistry
Divisions:College of Science > School of Life Sciences
ID Code:15131
Deposited On:08 Jun 2015 16:24

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