- Aurora C kinase is a serine/threonine kinase closely related to Aurora B and functions predominantly in germ cells, where it plays essential roles in meiosis, chromosome segregation and cytokinesis. Although Aurora C shares significant structural and functional similarity with Aurora B, its expression pattern, regulatory dynamics and biological importance are distinct. Aurora C is highly enriched in spermatocytes and oocytes, where it supports meiotic progression and ensures the accurate segregation of homologous chromosomes and sister chromatids. In somatic cells, Aurora C expression is normally low, but it can become upregulated in certain pathological conditions, including cancer.
- Aurora C forms a complex with the same core components as Aurora B — INCENP, Borealin and Survivin — collectively known as the Chromosomal Passenger Complex. Through this complex, Aurora C participates in centromere targeting, kinetochore regulation and cytokinesis. However, Aurora C displays unique localisation patterns during meiosis. In spermatocytes, Aurora C accumulates at centromeres during metaphase I and II, where it helps regulate kinetochore–microtubule interactions and tension sensing. Its activity ensures that homologous chromosomes segregate correctly during meiosis I and that sister chromatids separate accurately during meiosis II.
- Aurora C’s functional overlap with Aurora B has led to the concept of partial redundancy. In germ cells, Aurora C can compensate for Aurora B loss, maintaining CPC activity and supporting chromosome segregation. Conversely, overexpression of Aurora C in somatic cells can displace Aurora B from the CPC, leading to abnormal centromere targeting, defective kinetochore phosphorylation and impaired mitotic error correction. These disruptions contribute to chromosome mis‑segregation, aneuploidy and cytokinesis failure.
- Aurora C also plays a critical role in cytokinesis. During late meiosis and mitosis, Aurora C localises to the spindle midzone and midbody, where it regulates contractile ring formation and abscission. Defects in Aurora C activity lead to multinucleated germ cells, impaired spermatogenesis and infertility. Mouse models lacking Aurora C exhibit abnormal sperm morphology, defective meiotic progression and reduced fertility, highlighting its essential role in germ‑cell development.
- In cancer, Aurora C is frequently overexpressed, particularly in colorectal, breast and haematological malignancies. Elevated Aurora C levels correlate with chromosomal instability and aggressive tumour behaviour. Because Aurora C can substitute for Aurora B in the CPC, its overexpression may allow tumour cells to tolerate mitotic stress while maintaining high proliferation rates. Aurora C is therefore emerging as a potential therapeutic target, and inhibitors designed for Aurora B often show cross‑reactivity with Aurora C due to their structural similarity.
- In summary, Aurora C kinase is a germ‑cell‑enriched member of the Aurora kinase family that supports meiotic chromosome segregation, kinetochore regulation and cytokinesis. Although functionally related to Aurora B, Aurora C has distinct roles in meiosis and contributes to fertility, genomic stability and tumour progression. Its unique biology makes Aurora C an important focus of research in reproductive cell division and cancer therapeutics.
