Cyclin-dependent kinase 6 phosphorylates NF-κB P65 at serine 536 and contributes to the regulation of inflammatory gene expression

Holger Buss; Katja Handschick; Nadine Jurrmann; Pirita Pekkonen; Knut Beuerlein; Helmut Müller; Robin Wait; Jeremy Saklatvala; Päivi M Ojala; M Lienhard Schmitz; Michael Naumann; Michael Kracht

doi:10.1371/journal.pone.0051847

Cyclin-dependent kinase 6 phosphorylates NF-κB P65 at serine 536 and contributes to the regulation of inflammatory gene expression

PLoS One. 2012;7(12):e51847. doi: 10.1371/journal.pone.0051847. Epub 2012 Dec 26.

Authors

Holger Buss¹, Katja Handschick, Nadine Jurrmann, Pirita Pekkonen, Knut Beuerlein, Helmut Müller, Robin Wait, Jeremy Saklatvala, Päivi M Ojala, M Lienhard Schmitz, Michael Naumann, Michael Kracht

Affiliation

¹ Institute of Pharmacology, Medical School Hannover, Hannover, Germany.

Abstract

Nuclear factor kappa-B (NF-κB) activates multiple genes with overlapping roles in cell proliferation, inflammation and cancer. Using an unbiased approach we identified human CDK6 as a novel kinase phosphorylating NF-κB p65 at serine 536. Purified and reconstituted CDK6/cyclin complexes phosphorylated p65 in vitro and in transfected cells. The physiological role of CDK6 for basal as well as cytokine-induced p65 phosphorylation or NF-κB activation was revealed upon RNAi-mediated suppression of CDK6. Inhibition of CDK6 catalytic activity by PD332991 suppressed activation of NF-κB and TNF-induced gene expression. In complex with a constitutively active viral cyclin CDK6 stimulated NF-κB p65-mediated transcription in a target gene specific manner and this effect was partially dependent on its ability to phosphorylate p65 at serine 536. Tumor formation in thymi and spleens of v-cyclin transgenic mice correlated with increased levels of p65 Ser536 phosphorylation, increased expression of CDK6 and upregulaton of the NF-κB target cyclin D3. These results suggest that aberrant CDK6 expression or activation that is frequently observed in human tumors can contribute through NF-κB to chronic inflammation and neoplasia.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Apoptosis
Cell Nucleus / genetics
Cell Nucleus / metabolism
Cell Proliferation
Cyclin-Dependent Kinase 6 / antagonists & inhibitors
Cyclin-Dependent Kinase 6 / genetics
Cyclin-Dependent Kinase 6 / metabolism*
Gene Expression Regulation, Neoplastic*
HeLa Cells
Humans
I-kappa B Proteins / metabolism
Immunoblotting
Inflammation / genetics*
Inflammation / metabolism
Inflammation / pathology
Lymphocytes / metabolism
Lymphocytes / pathology
Mice
Mice, Transgenic
NF-kappa B / genetics
NF-kappa B / metabolism*
Phosphorylation
RNA, Small Interfering / genetics
Serine / chemistry
Serine / genetics
Serine / metabolism*
Splenic Neoplasms / genetics*
Splenic Neoplasms / metabolism
Splenic Neoplasms / pathology
Tandem Mass Spectrometry
Thymus Neoplasms / genetics*
Thymus Neoplasms / metabolism
Thymus Neoplasms / pathology
Tumor Necrosis Factor-alpha / pharmacology

Substances

I-kappa B Proteins
NF-kappa B
RNA, Small Interfering
Tumor Necrosis Factor-alpha
Serine
Cyclin-Dependent Kinase 6

Grants and funding

This work was supported by grants from the Deutsche Forschungsgemeinschaft Kr1143/7-1, TRR81 (B2), Na292/9-1, SFB854 (TP4). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.