Survivin mutant (Surv-DD70, 71AA) disrupts the interaction of Survivin with Aurora B and causes multinucleation in HeLa cells.

Survivin is associated with Aurora B, inner centromere protein (INCENP), and borealin to form a chromosomal passenger complex that plays multiple roles during cell division. We used mutational analysis to study interaction of Survivin with Aurora B and the effect of this interaction on cell division. A Survivin mutant with the terminal domain deleted (Survivin 1-107) bound Aurora B as efficiently as Survivin wild type. This indicated that the proximal BIR domain of Survivin was responsible for Survivin binding to Aurora B. Survivin mutants (Surv-R18A, Surv-D53A, and Sur-KK78, and 79AA) all bound to Aurora B efficiently, but mutation in the conserved amino acid residues of the acidic patch on Survivin (Surv-DD70, 71AA) abolished the direct interaction of Survivin and Aurora B. The Survivin mutant (Surv-DD70, 71AA) localized diffusely in metaphase and failed to successfully accumulate in the midbody during cytokinesis. Furthermore, over-expression of the Survivin mutant (Surv-DD70, 71AA) severely disturbed cytokinesis, resulting in multinucleation in HeLa cell. This indicated that the direct interaction of Survivin and Aurora B was critical for the correct location of Survivin and the function of the Survivin complex in cell division.