Aurora B kinase

Aurora B Kinase

Aurora B kinase is a serine/threonine-protein kinase that plays a crucial role in the regulation of mitosis. It is a part of the chromosomal passenger complex (CPC), which is essential for proper chromosome alignment, segregation, and cytokinesis during cell division. Aurora B kinase is a key player in ensuring the fidelity of mitosis and is involved in various cellular processes, including the correction of kinetochore-microtubule attachments and the regulation of the mitotic checkpoint.

Structure and Function

Aurora B kinase is one of the three members of the Aurora kinase family, which also includes Aurora A kinase and Aurora C kinase. It is characterized by a conserved kinase domain and a regulatory domain that is involved in its activation and localization.

Aurora B kinase functions as part of the chromosomal passenger complex, which also includes INCENP, Survivin, and Borealin. This complex is crucial for the localization of Aurora B to the centromeres and the central spindle during mitosis.

Role in Mitosis

During mitosis, Aurora B kinase is responsible for several key processes:

• Chromosome Condensation and Alignment: Aurora B phosphorylates histone H3, which is important for chromosome condensation. It also ensures proper alignment of chromosomes at the metaphase plate by correcting improper kinetochore-microtubule attachments.

• Spindle Assembly Checkpoint: Aurora B kinase is involved in the spindle assembly checkpoint, a safety mechanism that prevents the onset of anaphase until all chromosomes are properly attached to the spindle apparatus.

• Cytokinesis: Aurora B is essential for the final stages of cell division, where it regulates the formation of the contractile ring and the completion of cytokinesis.

Clinical Significance

Aurora B kinase is a target for cancer therapy due to its role in cell division. Overexpression or dysregulation of Aurora B has been observed in various cancers, making it a potential target for anticancer drugs. Inhibitors of Aurora B kinase, such as barasertib and danusertib, are being investigated in clinical trials for their efficacy in treating cancer.

Research and Development

Ongoing research is focused on understanding the detailed mechanisms of Aurora B kinase regulation and its interactions with other proteins during mitosis. Studies are also exploring the development of more selective and potent inhibitors that can be used in cancer therapy with minimal side effects.

Also see

• Aurora A kinase
• Aurora C kinase
• Chromosomal passenger complex
• Mitosis
• Spindle assembly checkpoint