CDK11^p58-cyclin L1β regulates abscission site assembly

Area of Science:

• Cell Biology
• Molecular Biology
• Genetics

Background:

• Cell division requires precise spatiotemporal control for genome stability.
• Abscission, the final cell separation stage, is regulated by the abscission checkpoint, primarily involving Aurora B kinase activity.
• Aurora B kinase inhibits abscission until chromosome segregation is complete.

Purpose of the Study:

• To investigate the role of CDK11^p58^ kinase in regulating abscission timing.
• To elucidate the mechanism by which CDK11^p58^ influences cell division completion.

Main Methods:

• Studied the complex formation of CDK11^p58^ with cyclin L1β.
• Investigated the localization of the CDK11^p58^/cyclin L1β complex during late cytokinesis.
• Utilized depletion and rescue experiments to assess CDK11 function.
• Examined the requirement of CDK11^p58^ activity for ESCRT-III filament formation.

Main Results:

• CDK11^p58^ forms a complex with cyclin L1β, localizing to the stem body during late cytokinesis.
• Depletion of CDK11 inhibits abscission, a phenotype rescued by active CDK11^p58^ or Aurora B inhibition.
• CDK11^p58^ kinase activity is essential for the formation of endosomal sorting complex required for transport III (ESCRT-III) filaments at the abscission site.

Conclusions:

• CDK11^p58^ kinase activity acts antagonistically to Aurora B kinase.
• This opposition is critical for timely abscission and successful completion of cytokinesis.
• The findings highlight CDK11^p58^ as a key regulator of cell division and genome stability.