CDK12-CCNK Heterodimer Protein, Human (sf9, GST, FLAG)

The CDK12 protein is a cyclin-dependent kinase that critically phosphorylates the C-terminal domain of POLR2A, thereby regulating transcription elongation. It selectively targets "Ser-5" phosphorylated at "Ser-7" in the CTD repeat and can also target "Ser-2". CDK12-CCNK Heterodimer Protein, Human (sf9, GST, FLAG) is a recombinant protein dimer complex containing human-derived CDK12-CCNK Heterodimer protein, expressed by sf9 insect cells , with N-Flag, N-GST labeled tag.

The CDK12-CCNK heterodimer protein functions as a cyclin-dependent kinase, playing a crucial role in transcription elongation by phosphorylating the C-terminal domain (CTD) of the large subunit of RNA polymerase II (POLR2A). This kinase is a key regulator of gene expression, particularly involved in DNA repair processes and the maintenance of genomic stability. Its phosphorylation activity is selective, preferring 'Ser-5' in CTD repeats already phosphorylated at 'Ser-7,' but it can also target 'Ser-2.' CDK12-CCNK is essential for RNA splicing, potentially through the phosphorylation of SRSF1/SF2. Additionally, it participates in the regulation of MAP kinase activity, suggesting its involvement in influencing responses to estrogen inhibitors.

The activity was measured by off-chip mobility shift assay(MSA). The enzyme was incubated with fluorecence-labeled substrate and Mg(or Mn)/ATP. The phosphorylated and unphosphorylated substrates were separated and detected by MSA device. The Km of CDK12-CCNK for its substrate is 30 μM.

Human

Sf9 insect cells

N-Flag;N-GST

Q9NYV4-1 (Q696-S1082)&O75909-1 (M1-S300)

51755&8812

71.4 kDa & 36.9 kDa

Greater than 90% as determined by reducing SDS-PAGE.

Solution.

Supplied as a 0.2 μm filtered solution of 20 mM HEPES, pH 7.5, 200 mM NaCl, 5% glycerol, 1 mM DTT.

<1 EU/μg, determined by LAL method.

Please use rapid thawing with running water to thaw the protein.

Stored at -80°C for 1 year from date of receipt. It is stable at -20°C for 3 months after opening. It is recommended to freeze aliquots at -80°C for extended storage. Avoid repeated freeze-thaw cycles.

Shipping with dry ice.