Cyclin C (E6V4Z) Rabbit mAb #68179

Cyclin dependent kinases (CDKs) are regulated in part through binding to regulatory cyclins. While many cyclin/CDK complexes regulate progression through the cell cycle, others, such as cyclin C/CDK8, regulate transcription and other cellular functions. Cyclin C/CDK8 forms a regulatory sub-complex with Med12 and Med13, which associates with the multi-subunit transcriptional coactivator Mediator Complex to modulate RNA polymerase II-dependent transcription. In addition to its role in transcription, cyclin C is important in the regulation of mitochondrial dynamics, apoptosis, and cell cycle progression (1). Cytosolic cyclin C induces mitochondrial fragmentation and apoptosis, and is required for activation of the Bcl2 family member, Bax (2). Cytoplasmic cyclin C also supports mitochondrial fission through dynamin-related protein 1 (Drp1) in response to oxidative stress (3). Cyclin C acts synergistically with PTEN to maintain levels of tumor suppressors p53 and p21 in a mouse model of thyroid cancer (4). In complex with CDK3, cyclin C regulates Rb-dependent exit from quiescence in human cells (5).