Mediator Complex Antibody Sampler Kit #43698

The mammalian Mediator complex is a multi-subunit protein complex that acts to relay signals from transcription factors to RNA polymerase II (Pol II) and the basal transcription machinery. In other words, Mediator acts as a centralized hub or integrator for transcriptional regulation (reviewed in 1,2). Multiple studies have shown that Mediator functions include epigenetic regulation, transcriptional elongation, transcription termination, mRNA processing, non-coding RNA activation, and super-enhancer formation. Through these functions, Mediator contributes to the regulation of many biological processes, including insulin signaling (3), NF-κB-dependent signaling (4), stem cell pluripotency and self-renewal (5,6), and proliferation of colon cancer cells (7,8). The Mediator complex consists of 31 protein subunits and can be divided into four distinct modules: the head, middle, tail, and CDK8 kinase module. The CDK8 kinase module contains the CDK8, cyclin C, MED12, and MED13 subunits and is thought to act as a molecular switch, phosphorylating the C-terminal domain (CTD) of Rpb1, the large subunit of Pol II, to inhibit Pol II recruitment and transcription initiation (9,10).