Cyclin-dependent kinase 1-cyclin B complex (CDK1-cyclin B) (CDK1-cyclin B)

The Cyclin-dependent kinase 1-cyclin B complex (CDK1-cyclin B), historically known as the Maturation Promoting Factor (MPF), is a master regulatory enzyme essential for the G2 to M phase transition in the eukaryotic cell cycle [2, 3]. It consists of the catalytic subunit Cyclin-dependent kinase 1 (CDK1) and its regulatory partner, Cyclin B (primarily Cyclin B1) [3, 10]. The activity of this complex is tightly regulated by inhibitory phosphorylation on Thr14 and Tyr15 by kinases such as WEE1, and its rapid activation at the onset of mitosis is triggered by the CDC25-mediated removal of these phosphates [11, 13]. Once activated, the complex phosphorylates numerous substrates to orchestrate critical mitotic events, including nuclear envelope breakdown, chromosome condensation, and spindle assembly [9, 13]. In many cancers, the CDK1-cyclin B complex is overexpressed or dysregulated, driving the rapid and unchecked cell proliferation that characterizes malignancy [1, 4]. Consequently, it has become a significant target for small-molecule inhibitors, such as Dinaciclib and Flavopiridol, which aim to induce mitotic arrest and apoptosis in tumor cells [7, 9]. However, the high structural similarity between CDK1 and other CDKs presents a major challenge for achieving therapeutic selectivity, often leading to dose-limiting toxicities like neutropenia and gastrointestinal distress [6, 7]. Beyond its role in the cell cycle, recent studies have also implicated the complex in regulating cell migration and invasion, further highlighting its importance in cancer progression [5, 14].

Other names

Maturation promoting factor (MPF)Mitosis promoting factor (MPF)CDK1-CCNB1 complexCDC2-cyclin B complexp34cdc2-cyclin B complex

ATP-competitive inhibition of CDK1 kinase activity, leading to G2/M phase arrest and induction of apoptosis in malignant cells.