Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Old Road Campus, Roosevelt Drive, Oxford, OX3 7DQ, UK.
Biomolecular and Analytical Mass Spectrometry, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium.
Nat Commun. 2019 Jul 18;10(1):3166. doi: 10.1038/s41467-019-11085-0.
Aurora kinases B and C (AURKB/AURKC) are activated by binding to the C-terminal domain of INCENP. Full activation requires phosphorylation of two serine residues of INCENP that are conserved through evolution, although the mechanism of this activation has not been explained. Here we present crystal structures of the fully active complex of AURKC bound to INCENP, consisting of phosphorylated, activated, AURKC and INCENP phosphorylated on its TSS motif, revealing the structural and biochemical mechanism of synergistic activation of AURKC:INCENP. The structures show that TSS motif phosphorylation stabilises the kinase activation loop of AURKC. The TSS motif phosphorylations alter the substrate-binding surface consistent with a mechanism of altered kinase substrate selectivity and stabilisation of the protein complex against unfolding. We also analyse the binding of the most specific available AURKB inhibitor, BRD-7880, and demonstrate that the well-known Aurora kinase inhibitor VX-680 disrupts binding of the phosphorylated INCENP TSS motif.
极光激酶 B 和 C（AURKB/AURKC）通过与 INCENP 的 C 末端结构域结合而被激活。完全激活需要 INCENP 上两个丝氨酸残基的磷酸化，这些残基在进化过程中是保守的，尽管这种激活的机制尚未得到解释。在这里，我们展示了与 INCENP 结合的完全激活的 AURKC 复合物的晶体结构，该复合物由磷酸化、激活的 AURKC 和 INCENP 在其 TSS 基序上磷酸化组成，揭示了 AURKC：INCENP 协同激活的结构和生化机制。结构显示 TSS 基序磷酸化稳定了 AURKC 的激酶激活环。TSS 基序磷酸化改变了底物结合表面，与改变激酶底物选择性和稳定蛋白复合物防止展开的机制一致。我们还分析了最特异的可用 AURKB 抑制剂 BRD-7880 的结合，并证明了众所周知的 Aurora 激酶抑制剂 VX-680 破坏了磷酸化 INCENP TSS 基序的结合。
