PKCbetaII augments NF-kappaB-dependent transcription at the CCL11 promoter via p300/CBP-associated factor recruitment and histone H4 acetylation.
The transcription factor NF-kappaB plays a pivotal role in regulating inflammatory gene expression. Its effects are optimized by various coactivators, including histone acetyltransferases (HATs) such as CREB-binding protein/p300 and p300/CBP-associated factor (p/CAF). The molecular mechanisms regulating cofactor recruitment are poorly understood. In this study, we describe a novel role for protein kinase C (PKC) betaIotaIota in augmenting NF-kappaB-mediated TNF-alpha-induced transcription of the target gene CCL11 in human airway smooth muscle cells by phosphorylating the HAT p/CAF. Studies using reporters, overexpression strategies, kinase-dead and HAT-defective mutants, and chromatin immunoprecipitation showed that PKCbetaII activation was not involved in NF-kappaB translocation, but facilitated NF-kappaB-mediated CCL11 transcription by colocalizing with and phosphorylating p/CAF, and thereby acetylating histone H4 and promoting p65 association with the CCL11 promoter. The effect was dependent on p/CAF's HAT activity. Furthermore, mouse embryonic fibroblasts from PKCbeta knockout mice showed markedly reduced TNF-alpha-induced CCL11 expression and NF-kappaB reporter activity that was restored on PKCbetaII overexpression, suggesting a critical role for this pathway. These data suggest a novel important biological role for PKCbetaIotaIota in NF-kappaB-mediated CCL11 transcription by p/CAF activation and histone H4 acetylation.
Clarke
Deborah L
DL
Division of Respiratory Medicine, University of Nottingham, City Hospital, Nottingham, United Kingdom.
Sutcliffe
Amy
A
Deacon
Karl
K
Bradbury
Dawn
D
Corbett
Lisa
L
Knox
Alan J
AJ
D000107:Acetylation; D000328:Adult; D000818:Animals; D002478:Cells, Cultured; D054413:Chemokine CCL11 / Q000235:genetics*; D050881:E1A-Associated p300 Protein / Q000378:metabolism*; D005260:Female; D006657:Histones / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D032389:Myocytes, Smooth Muscle; D016328:NF-kappa B / Q000502:physiology*; D011401:Promoter Regions, Genetic; D011493:Protein Kinase C / Q000502:physiology*; D064546:Protein Kinase C beta; D021381:Protein Transport; D012137:Respiratory System; D051996:Transcription Factor RelA / Q000502:physiology*; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha
D054413:Chemokine CCL11; D006657:Histones; D016328:NF-kappa B; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human; D011493:Protein Kinase C; D064546:Protein Kinase C beta