BICD2 phosphorylation regulates dynein function and centrosome separation in G2 and M

Area of Science:

• Cell Biology
• Molecular Motor Regulation
• Protein Phosphorylation

Background:

• Dynein motor protein activity is regulated by adaptors that link it to various cellular cargos.
• The precise mechanisms controlling dynein adaptor regulation remain largely uncharacterized.
• BICD2 is a well-established adaptor protein involved in dynein-mediated cellular processes.

Purpose of the Study:

• To investigate the regulatory mechanisms governing BICD2 adaptor protein activity.
• To elucidate the role of phosphorylation in BICD2 function and dynein complex formation.

Main Methods:

• Investigated protein-protein interactions using biochemical assays.
• Analyzed the effects of specific phosphorylation events on BICD2 structure and function.
• Utilized cell cycle synchronization and microscopy to study dynein recruitment and centrosome dynamics.

Main Results:

• BICD2 phosphorylation by CDK1 promotes its interaction with PLK1.
• PLK1-mediated phosphorylation of BICD2 induces a conformational change, facilitating dynein and dynactin binding.
• Phosphorylated BICD2 preferentially binds to phosphorylated RanBP2, influencing dynein recruitment to the nuclear envelope and centrosome positioning during cell division.

Conclusions:

• Adaptor protein activation via phosphorylation is a critical mechanism for spatiotemporal control of dynein activity.
• BICD2 phosphorylation by CDK1 and PLK1 is essential for dynein-mediated nuclear envelope recruitment, centrosome tethering, and centrosome separation in G2/M phases.
• This study reveals a novel regulatory pathway for dynein motor complex activation.