Cyclin N-terminal domain-containing protein 1 (CNTD1)

Cyclin N-terminal domain-containing protein 1 (CNTD1) is a cyclin-like protein primarily involved in coordinating meiotic crossover formation and cell-cycle progression in germ cells, notably in mammals. CNTD1 is a regulator of meiotic recombination required for the differentiation and maturation of crossover-specific recombination complexes during meiosis. CNTD1 acts in a complex with PRR19 and is essential for the repair of programmed DNA double-strand breaks. Unlike canonical cyclins, mouse CNTD1 exists in a shortened form that does not bind cyclin-dependent kinases but instead interacts with the Replication Factor C (RFC) complex and the SKP1-Cullin-Fbox (SCF) complex, influencing both crossover formation (by regulating MLH1-MLH3 function) and cell cycle control (by facilitating degradation of WEE1 kinase to allow cell-cycle progression). The protein plays a "stop-go" regulatory role during meiotic prophase I, ensuring chromosomal crossovers are completed before metaphase progression and the first meiotic division proceed. Loss of CNTD1 function impairs crossover differentiation and delays DSB repair, leading to reproductive defects such as infertility. CNTD1 is not a classical cyclin: it lacks a canonical cyclin box domain and does not bind cyclin-dependent kinases in vivo. It is not targeted by drugs and has no current use as a clinical biomarker or therapeutic target.

Other names

Cyclin N-terminal domain-containing protein 1CNTD1CNTDFLJ40137COSA1