Fig. 8: A working model explaining the mechanism by which Aurora B activation and kinase activity are regulated by K63-lined ubiquitination.

a The crystal structure of human Aurora B kinase in complex with INCENP and VX-680 (PDB ID: 4AF3)⁵⁸. K202 (red) is located in the activation loop (purple) of Aurora B (green). b Magnified view showing the position of K202 and surrounding DFG (Asp-Phe-Gly) motif at the start of the activation loop. The crystal structure of human Aurora B Kinase provides us with strong support. We propose that ubiquitination at K202 might be critical for the autoactivation of Aurora B, which in turn facilitates the phosphorylation of TSS in INCENP, required for CPC complex formation and full activation of Aurora B. c Schematic showing BRISC-regulated K63-Ubs of Aurora B is important for creating a dynamic gradient Aurora B kinase activity to ensure correct KT-MT attachment and chromosome segregation.