Centrioles resist forces applied on centrosomes during G2/M transition

Area of Science:

• Cell Biology
• Mitosis
• Cytoskeleton Dynamics

Background:

• Centrosome movements during mitosis are governed by microtubule-mediated forces.
• Centriole stability is linked to heavy polyglutamylation of tubulin.

Purpose of the Study:

• To investigate the role of polyglutamylated tubulin in maintaining centrosome integrity during cell division.
• To understand how centrosomes respond to mechanical forces in G2/M phase.

Main Methods:

• Microinjection of anti-(polyglutamylated tubulin) antibody (GT335) into HeLa cells.
• Monitoring centrosome behavior in G1/S and G2 phases using centrin-green fluorescent protein.
• Assessing the impact of motor protein inhibition (Eg5, dynein) and microtubule dynamics disruption.

Main Results:

• Microinjection of GT335 induced rapid centrosome fragmentation in G2 cells, but not in G1/S.
• Fragmentation was dependent on Eg5 and dynein motor proteins.
• Inhibition of microtubule dynamics abolished fragmentation, indicating a role for microtubule-based forces.

Conclusions:

• The mitotic centrosome's compact structure withstands mechanical forces during the G2/M transition.
• Centrosomes may function as mechanosensors, integrating cellular tension during division.