Phospho-CDK1 (Tyr15) Recombinant Rabbit mAb (S-6330)

Phospho-CDK1 (Tyr15) refers to the inactive form of cyclin-dependent kinase 1 (CDK1) generated upon phosphorylation at the Tyr15 residue, and represents a core molecular event in G2/M checkpoint regulation. Once CDK1 binds Cyclin B, it is poised to drive cells into mitosis, but phosphorylation of Tyr15 by Wee1 kinase inhibits its kinase activity, causing cells to arrest in G2 phase to allow completion of DNA repair or to cope with replication stress. When cells are ready to divide, the Cdc25 phosphatase removes the phosphate group at Tyr15, and CDK1 becomes activated and triggers mitotic entry. In experimental detection, the phosphorylation level at Tyr15 is commonly used as a marker of CDK1 inactivation and G2/M arrest: low levels of phospho-CDK1 (Tyr15) indicate that CDK1 is activated and cells are entering mitosis, whereas elevated phosphorylation at this site reflects checkpoint activation or suppression of CDK1 activity. In clinically relevant studies, combined detection of phospho-CDK1 (Tyr15) and dephosphorylated CDK1 has been used to assess prognosis in non-small cell lung cancer, with both showing prognostic significance.