Regulation of RelB expression during the initiation of dendritic cell differentiation.
The transcription factor RelB is required for proper development and function of dendritic cells (DCs), and its expression is upregulated early during differentiation from a variety of progenitors. We explored this mechanism of upregulation in the KG1 cell line model of a DC progenitor and in the differentiation-resistant KG1a subline. RelB expression is relatively higher in untreated KG1a cells but is upregulated only during differentiation of KG1 by an early enhancement of transcriptional elongation, followed by an increase in transcription initiation. Restoration of protein kinase CbetaII (PKCbetaII) expression in KG1a cells allows them to differentiate into DCs. We show that PKCbetaII also downregulated constitutive expression of NF-kappaB in KG1a-transfected cells and restores the upregulation of RelB during differentiation by increased transcriptional initiation and elongation. The two mechanisms are independent and sensitive to PKC signaling levels. Conversely, RelB upregulation was inhibited in primary human monocytes where PKCbetaII expression was knocked down by small interfering RNA targeting. Altogether, the data show that RelB expression during DC differentiation is controlled by PKCbetaII-mediated regulation of transcriptional initiation and elongation.
Cejas
Pedro J
PJ
University of Miami School of Medicine, Department of Microbiology and Immunology, FL 33136, USA.
Carlson
Louise M
LM
Kolonias
Despina
D
Zhang
Jian
J
Lindner
Inna
I
Billadeau
Daniel D
DD
Boise
Lawrence H
LH
Lee
Kelvin P
KP
D002454:Cell Differentiation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D011401:Promoter Regions, Genetic / Q000235:genetics; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D064546:Protein Kinase C beta; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D020871:RNA Stability; D034741:RNA, Small Interfering / Q000235:genetics; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D051841:Transcription Factor RelB; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics
D011518:Proto-Oncogene Proteins; C497593:RELB protein, human; D034741:RNA, Small Interfering; D014157:Transcription Factors; D051841:Transcription Factor RelB; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D013755:Tetradecanoylphorbol Acetate