Chromatin-Associated Protein Kinase C-θ Regulates an Inducible Gene Expression Program and MicroRNAs in Human T Lymphocytes

SummaryStudies in yeast demonstrate that signaling kinases have a surprisingly active role in the nucleus, where they tether to chromatin and modulate gene expression programs. Despite these seminal studies, the nuclear mechanism of how signaling kinases control transcription of mammalian genes is in its infancy. Here, we provide evidence for a hitherto unknown function of protein kinase C-theta (PKC-θ), which physically associates with the regulatory regions of inducible immune response genes in human T cells. Chromatin-anchored PKC-θ forms an active nuclear complex by interacting with RNA polymerase II, the histone kinase MSK-1, and the adaptor molecule 14-3-3ζ. ChIP-on-chip reveals that PKC-θ binds to promoters and transcribed regions of genes, as well as to microRNA promoters that are crucial for cytokine regulation. Our results provide a molecular explanation for the role of PKC-θ not only in normal T cell function, but also in circumstances of its ectopic expression in cancer.

► PKC-θ belongs in an emerging class of mammalian signaling kinases in human T cells
► Chromatin-anchored PKC-θ forms an active transcription complex on immune genes
► ChIP-on-chip reveals PKC-θ negatively regulates microRNAs by direct association
► Interplay between kinases, chromatin regulation and microRNAs in higher eukaryotes