CDK19 Full-Length MS Protein Standard (NP_055891), Labeled with [U- 13C6, 15N4]-L-Arginine and [U- 13C6, 15N2]-L-Lysine, was produced in human 293 cells (HEK293) with fully chemically defined cell culture medium to obtain incorporation efficiency at Creative-Proteomics. This gene encodes a protein that is one of the components of the Mediator co-activator complex. The Mediator complex is a multi-protein complex required for transcriptional activation by DNA binding transcription factors of genes transcribed by RNA polymerase II. The protein encoded by this gene is similar to cyclin-dependent kinase 8 which can also be a component of the Mediator complex. Alternative splicing results in multiple transcript variants encoding distinct isoforms.