Cyclin C/CDK8 is a novel CTD kinase associated with RNA polymerase II.

摘要: A number of cyclin/kinase complexes have been identified in mammalian cells that are essential for controlled cell proliferation. Cyclin C was isolated by virtue its ability to rescue the triple CLN mutation yeast; however, until now function has remained unclear. associates with a novel cyclin dependent kinase, CDK8, and we demonstrate this complex is associated kinase activity towards carboxy-terminal domain (CTD) RNA polymerase II. We at least two distinct C/CDK8 containing within cell, larger over 500 kD size, also contains largest subunit II, smaller 170 species. Both these retain potent CTD activity. further large II vivo, implicating potential role regulating activities.