Tag: Mitosis

Post-translational modifications are essential regulators of cell-cycle progression. Learn how phosphorylation, ubiquitination, acetylation, SUMOylation, methylation, and other PTMs control CDKs, cyclins, checkpoints, DNA replication, mitosis, and protein degradation.

Aurora A kinase is a key regulator of centrosome maturation and spindle assembly. By controlling microtubule dynamics, centrosome separation and chromosome alignment, Aurora A ensures accurate mitotic progression. Its frequent overexpression in cancer highlights its importance in genomic stability and tumour development.

The kinetochore is a dynamic protein complex assembled on centromeric chromatin that binds spindle microtubules, generates tension and ensures accurate chromosome segregation. Through coordinated interactions with Aurora B kinase and spindle checkpoint signalling, the kinetochore maintains mitotic fidelity and prevents aneuploidy.

The spindle assembly checkpoint (SAC) is a mitotic surveillance system that prevents premature anaphase onset by monitoring kinetochore–microtubule attachment and tension. Through coordinated action with Aurora B kinase and the Chromosomal Passenger Complex, the SAC ensures accurate chromosome segregation and protects cells from aneuploidy.

Aurora B kinase is the catalytic core of the Chromosomal Passenger Complex, ensuring accurate chromosome segregation, correcting kinetochore–microtubule attachment errors and coordinating cytokinesis. Its central role in mitotic fidelity and frequent dysregulation in cancer make Aurora B a major therapeutic target.

Borealin (CDCA8) is the structural stabiliser of the Chromosomal Passenger Complex. By anchoring Aurora B, INCENP and Survivin to centromeres and guiding CPC relocation to the spindle midzone, Borealin ensures accurate chromosome segregation and successful cytokinesis.

INCENP is the structural and regulatory scaffold of the Chromosomal Passenger Complex. By activating Aurora B kinase, binding microtubules and directing CPC movement from centromeres to the spindle midzone, INCENP ensures accurate chromosome segregation and successful cytokinesis.

The Chromosomal Passenger Complex (CPC) is a dynamic mitotic regulator composed of Aurora B, INCENP, Borealin and Survivin. It ensures accurate chromosome segregation, corrects spindle attachment errors and coordinates cytokinesis, making it essential for genomic stability and highly relevant in cancer biology.

Survivin (BIRC5) is a tumour‑specific IAP that integrates apoptosis suppression with essential mitotic functions. As part of the chromosomal passenger complex, Survivin ensures proper chromosome segregation while stabilising anti‑apoptotic pathways, making it a central driver of tumour progression and therapy resistance.

Timely protein degradation is essential for orderly cell-cycle progression. Explore key cell-cycle regulators, their degradation mechanisms, and how their turnover controls G1/S transition, mitosis, chromosome segregation and mitotic exit.

Cdc20 is a key activator of the APC/C complex, initiating the metaphase‑to‑anaphase transition by promoting securin and Cyclin B degradation. Regulated by checkpoint proteins such as Mad2 and BubR1, Cdc20 safeguards chromosome segregation, while its dysregulation contributes to aneuploidy and cancer progression.

The ubiquitin-proteasome system is the master regulator of the cell cycle, controlling cyclin degradation, checkpoint progression, and mitotic exit. This comprehensive guide covers UPS mechanisms in G1/S transition, S phase, mitosis, and cancer therapy.