Cyclin B1 protein (Cyclin B1)

Cyclin B1 is a highly conserved regulatory protein encoded by the CCNB1 gene and is the key mitotic cyclin in mammals[3][6]. It forms a complex with cyclin-dependent kinase 1 (CDK1), known as maturation promoting factor (MPF), which is essential for initiating and regulating the progression of mitosis through the phosphorylation of critical substrates involved in chromosome condensation, nuclear envelope disassembly, and spindle assembly[2][3][6]. Cyclin B1 localization changes dynamically during cell division, being critical for directing CDK1 activity to distinct cellular structures such as centrosomes, chromatin, and kinetochores[1]. It is essential for cell division from the earliest stages of embryonic development[7]. Cyclin B1 is frequently overexpressed in diverse cancers, where it fosters tumor progression and is associated with poor prognosis, making it a promising but challenging target for anticancer drug development[2][3]. There are no approved drugs that specifically and directly target Cyclin B1 alone, but it is targeted indirectly via the Cyclin B1–CDK1 complex by several investigational CDK inhibitors. Monitoring Cyclin B1 expression serves as a biomarker for cell proliferation and malignancy in tumors. Inhibition of this protein poses clinical challenges due to its essential function in normal proliferating tissues and in embryogenesis[7].

Other names

G2/mitotic-specific cyclin-B1CCNB1

Inhibition of Cyclin B1–CDK1 complex formation, inhibition of kinase activity, cell cycle arrest at G2/M phase, induction of mitotic catastrophe or apoptosis