Protein kinase C-dependent activation of NF-kappa B in enterocytes is independent of I kappa B degradation

Citation
L. Wilson et al., Protein kinase C-dependent activation of NF-kappa B in enterocytes is independent of I kappa B degradation, GASTROENTY, 117(1), 1999, pp. 106-114
Citations number
27
Categorie Soggetti
Gastroenerology and Hepatology","da verificare
Journal title
GASTROENTEROLOGY
ISSN journal
00165085 → ACNP
Volume
117
Issue
1
Year of publication
1999
Pages
106 - 114
Database
ISI
SICI code
0016-5085(199907)117:1<106:PKCAON>2.0.ZU;2-W
Abstract
Background & Aims: Nuclear translocation of the NF-kappa B family of transc ription factors is a proximal step in the signal transduction of a pleiotro pic group of proinflammatory genes. Activation of RelA is under the negativ e control of I kappa B, a family of proteins degraded in response to immuno logic and oxidant stimuli. The aim of this study was to examine this mechan ism of NF-kappa B activation in intestinal epithelial cells. Methods: DLD-1 cell monolayers stimulated by interleukin (Il)-1 beta or phorbol myristate acetate (PMA) were assayed for the nuclear translocation of NF-kappa B and immunoreactivity of various I kappa B isoforms that regulate NF-kappa B1/R elA activation. Results: NF-kappa B activation triggered by PMA was not ass ociated with the disappearance of immunoreactive I kappa B alpha, I kappa B beta, I kappa B gamma, or I kappa B epsilon or With the dissociation of in tact I kappa B from RelA. NF-kappa B activation induced by PMA was blocked by the protein kinase C inhibitor staurosporine but not by the proteasomal Inhibitor N-acetyl-leucine leucine norleucinal (ALLN). In contrast, IL-1 be ta-induced NF-kappa B activation was associated with the disappearance of I kappa B alpha and was inhibited by ALLN but not staurosporine. Conclusions : Our data imply the existence of a novel pathway of NF-kappa B activation mediated by protein kinase C that does not require proteosomal degradation or the loss of I kappa B.