Cyclin-dependent kinase 2–Cyclin E1 complex (CDK2–Cyclin E1 complex (CDK2/CCNE1 complex))

The Cyclin-dependent kinase 2–Cyclin E1 complex is a critical serine/threonine kinase holoenzyme essential for the regulation of the eukaryotic cell cycle, specifically controlling the G1 to S phase transition[2][5][6]. The complex is formed by the association of CDK2 (cyclin-dependent kinase 2), an enzyme, and Cyclin E1 (encoded by the CCNE1 gene), a regulatory subunit[2][5]. Upon binding, Cyclin E1 induces a conformational activation of CDK2, enabling it to phosphorylate multiple substrates involved in DNA replication, cell cycle gene transcription, and centrosome duplication[5][2]. Dysregulation, especially overexpression or amplification of Cyclin E1 or hyperactivity of the complex, is a hallmark of several malignancies, making the CDK2–Cyclin E1 complex a validated, though challenging, anticancer therapeutic target[2][5][6][7]. Numerous small-molecule inhibitors are in clinical and preclinical development aimed at disrupting the kinase activity or the protein-protein interaction interface. Selectivity concerns and potential for toxicity due to the essential physiological function of the complex in normal cell proliferation are important therapeutic considerations[7].

Other names

CDK2–Cyclin E1 complexCyclin E1/CDK2 complexCyclin E/CDK2 complexCDK2/CCNE1 complex

Inhibition of CDK2 kinase activity (ATP-competitive or allosteric inhibition)[7] Disruption of CDK2–Cyclin E1 interaction Prevents phosphorylation of downstream substrates required for S-phase entry, halting cell cycle progression and cellular proliferation