Cyclin E1 protein (Cyclin E (often abbreviated as CCNE1 when referring to the human gene))

Cyclin E1 protein is a member of the cyclin family, encoded by the CCNE1 gene in humans, and acts as a regulatory subunit binding and activating cyclin-dependent kinase 2 (CDK2). The Cyclin E1/CDK2 complex is essential for the G1/S phase transition in the cell cycle, phosphorylating several critical substrates including retinoblastoma protein (Rb), p27, p21, and others, which collectively drive entry into DNA synthesis and cell proliferation. Degradation of Cyclin E1 ensures proper cell cycle timing, while its overexpression or deregulation is commonly observed in cancers, leading to chromosomal instability and increased tumorigenic potential. Cyclin E1 is being investigated as a cancer biomarker and as a potential therapeutic target via indirect inhibition of Cyclin E1/CDK2 kinase activity[1][3][7].

Other names

Cyclin ECCNE1 (gene symbol)G1/S-specific cyclin-E1

Inhibitors (typically of CDK2) block Cyclin E1/CDK2 kinase activity, halting progression from G1 to S phase, thereby inducing cell cycle arrest and potentially apoptosis in rapidly dividing cancer cells[1][3].