Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, United States of America.
PLoS Genet. 2022 Sep 9;18(9):e1010358. doi: 10.1371/journal.pgen.1010358. eCollection 2022 Sep.
Stu2 in S. cerevisiae is a member of the XMAP215/Dis1/CKAP5/ch-TOG family of MAPs and has multiple functions in controlling microtubules, including microtubule polymerization, microtubule depolymerization, linking chromosomes to the kinetochore, and assembly of γ-TuSCs at the SPB. Whereas phosphorylation has been shown to be critical for Stu2 localization at the kinetochore, other regulatory mechanisms that control Stu2 function are still poorly understood. Here, we show that a novel form of Stu2 regulation occurs through the acetylation of three lysine residues at K252, K469, and K870, which are located in three distinct domains of Stu2. Alteration of acetylation through acetyl-mimetic and acetyl-blocking mutations did not impact the essential function of Stu2. Instead, these mutations lead to a decrease in chromosome stability, as well as changes in resistance to the microtubule depolymerization drug, benomyl. In agreement with our in silico modeling, several acetylation-mimetic mutants displayed increased interactions with γ-tubulin. Taken together, these data suggest that Stu2 acetylation can govern multiple Stu2 functions, including chromosome stability and interactions at the SPB.
酿酒酵母中的 Stu2 是 XMAP215/Dis1/CKAP5/ch-TOG 家族 MAP 的成员，在控制微管方面具有多种功能，包括微管聚合、微管解聚、将染色体与动粒连接，以及 γ-TuSCs 在 SPB 处的组装。虽然已经表明磷酸化对于 Stu2 在动粒处的定位至关重要，但其他控制 Stu2 功能的调节机制仍知之甚少。在这里，我们表明通过在三个不同的 Stu2 结构域中的 K252、K469 和 K870 三个赖氨酸残基的乙酰化，发生了一种新型的 Stu2 调节形式。通过乙酰模拟和乙酰阻断突变改变乙酰化状态不会影响 Stu2 的基本功能。相反，这些突变导致染色体稳定性降低，以及对微管解聚药物苯并咪唑的抗性发生变化。与我们的计算机建模一致，几个乙酰化模拟突变体显示出与 γ-微管蛋白的相互作用增加。总之，这些数据表明 Stu2 乙酰化可以控制多种 Stu2 功能，包括染色体稳定性和 SPB 处的相互作用。
