
Product Description
CDK9/CyclinK is a serine/threonine kinase complex composed of the catalytic subunit CDK9 (cyclin-dependent kinase 9) and the regulatory subunit Cyclin K, which plays a pivotal role in transcriptional regulation, specifically in promoting RNA polymerase II (RNAPII) pause release and elongation. The CDK9/CyclinK complex phosphorylates the C-terminal domain (CTD) of RNAPII and other transcription-associated factors, thereby facilitating productive transcription elongation of genes involved in cell growth, differentiation, and survival. Beyond its essential physiological functions in gene expression, dysregulation of CDK9/CyclinK signaling—including overexpression, aberrant activation, and altered complex formation—is frequently observed in a wide range of human cancers, such as hematologic malignancies, prostate cancer, breast cancer, and neuroblastoma, contributing to uncontrolled proliferation, anti-apoptotic gene expression, and therapeutic resistance. These features have established CDK9/CyclinK as a highly validated target for cancer therapy and drug discovery.
Screeningbio’s CDK9/CyclinK Kinase Assay Kit provides a robust, sensitive, and high-throughput platform for quantifying CDK9/CyclinK kinase activity and evaluating the potency of tyrosine kinase inhibitors (TKIs).
This kit utilizes the ADP-Glo Kinase Assay platform, a luminescent technology that measures the amount of ADP produced during the kinase reaction.
The assay is performed in two distinct steps:
Kinase Reaction: CDK9/CyclinK catalyzes the transfer of a phosphate group from ATP to a specific substrate, resulting in the production of phosphorylated substrate and ADP.
ADP-Glo™ Reagent Addition: After the kinase reaction, the ADP-Glo™ Reagent is added to terminate the reaction and deplete any remaining unreacted ATP.
Kinase Detection: The Kinase Detection Reagent is added to simultaneously convert the produced ADP back into ATP, which is then used by luciferase to generate a luminescent signal.
The light intensity produced is directly proportional to the ADP concentration and, consequently, to the enzymatic activity of the CDK9/CyclinK kinase.
Data
![TKs Kinase Inhibition Assay. Staurosporine was titrated using established assay protocol. Non-linear regression was used to plot RLU signal vs. [Compound, M], and EC50 /IC50 values were determined, using GraphPad Prism software.](https://static.wixstatic.com/media/cbf7de_4a3efc69ff7a4f7f8a0a852643b9fdaf~mv2.png/v1/fill/w_49,h_45,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/cbf7de_4a3efc69ff7a4f7f8a0a852643b9fdaf~mv2.png)
