Product Description

Cyclin-dependent kinases (CDKs) are a family of serine/threonine kinases that play central roles in regulating the eukaryotic cell cycle. Their activity depends on association with specific cyclins, which control CDK activation at distinct cell cycle phases. For example, CDK4/6–cyclin D complexes drive G1 phase progression, while CDK1–cyclin B controls entry into mitosis. CDKs function by phosphorylating key substrates that govern DNA replication, mitotic entry, and transcriptional regulation. Beyond cell cycle control, several CDKs (e.g., CDK7, CDK9) are involved in transcriptional regulation via phosphorylation of RNA polymerase II. Dysregulation of CDK activity is frequently observed in cancer, leading to uncontrolled proliferation. Consequently, selective CDK inhibitors such as palbociclib, ribociclib, and abemaciclib have been developed as targeted therapies, particularly for breast cancer, underscoring the critical role of CDKs in both normal cellular homeostasis and oncogenesis.

Screeningbio’s TR-FRET CDKs kinase assay kit is designed to measure the relative activity levels of kinases. The kit uses a specific CDKs kinase substrate and detection reagents to evaluate kinase activity. Cyclin-dependent kinases (CDKs) constitute a large family, including CDK1/3/4/6/7/9/10/12/13/15–18, which specifically recognize and phosphorylate the Retinoblastoma-associated protein (Rb) at serine residue 780 (S780). Therefore, this kit employs an optimized Rb (S780) peptide as a substrate, coupled with TR-FRET LA(TR-FRET Acceptor) and TR-FRET Solar Eu conjugates(TR-FRET Donor), together with a phospho-Rb (S780)–specific antibody. This allows kinase activity to be quantified by detecting the level of phosphorylated substrate.