Dynamic acetylation of the kinetochore-associated protein HEC1 ensures accurate microtubule-kinetochore attachment [Computational Biology]

Faithful chromosome segregation during mitosis is critical for maintaining genome integrity in cell progeny and relies on accurate and robust kinetochore–microtubule attachments. The NDC80 complex, a tetramer comprising kinetochore protein HEC1 (HEC1), NDC80 kinetochore complex component NUF2 (NUF2), NDC80 kinetochore complex component SPC24 (SPC24), and SPC25, plays a critical role in kinetochore–microtubule attachment. Mounting evidence indicates that phosphorylation of HEC1 is important for regulating the binding of the NDC80 complex to microtubules. However, it remains unclear whether other post-translational modifications, such as acetylation, regulate NDC80–microtubule attachment during mitosis. Here, using pulldown assays with HeLa cell lysates and site-directed mutagenesis, we show that HEC1 is a bona fide substrate of the lysine acetyltransferase Tat-interacting protein, 60 kDa (TIP60) and that TIP60-mediated acetylation of HEC1 is essential for accurate chromosome segregation in mitosis. We demonstrate that TIP60 regulates the dynamic interactions between NDC80 and spindle microtubules during mitosis and observed that TIP60 acetylates HEC1 at two evolutionarily conserved residues, Lys-53 and Lys-59. Importantly, this acetylation weakened the phosphorylation of the N-terminal HEC1(1–80) region at Ser-55 and Ser-62, which is governed by Aurora B and regulates NDC80–microtubule dynamics, indicating functional cross-talk between these two post-translation modi...

Source: Journal of Biological Chemistry - January 11, 2019 Category: Chemistry Authors: Gangyin Zhao, Yubao Cheng, Ping Gui, Meiying Cui, Wei Liu, Wenwen Wang, Xueying Wang, Mahboob Ali, Zhen Dou, Liwen Niu, Haiyan Liu, Leonard Anderson, Ke Ruan, Jingjun Hong, Xuebiao Yao Tags: Cell Biology Source Type: research