a protein kinase of the CDK family. Along with cyclin C forms part of the RNA polymerase II holoenzyme complex. Phosphorylates the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II. Regulates transcription by targeting the CDK7/cyclin H subunits of the general transcription initiation factor IIH (TFIIH), thus providing a link between the 'Mediator-like' protein complexes and the basal transcription machinery. Note: This description may include information from UniProtKB.
Protein type: CDK family; CDK8 subfamily; CMGC group; Cell cycle regulation; EC 220.127.116.11; EC 18.104.22.168; Kinase, protein; Protein kinase, CMGC; Protein kinase, Ser/Thr (non-receptor)