CENP-A 的必需性取决于其与 HJURP 的结合模式。

Essentiality of CENP-A Depends on Its Binding Mode to HJURP.

机构信息

Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan.

出版信息

Cell Rep. 2020 Nov 17;33(7):108388. doi: 10.1016/j.celrep.2020.108388.

DOI:10.1016/j.celrep.2020.108388

PMID:33207191

Abstract

CENP-A incorporation is critical for centromere specification and is mediated by the chaperone HJURP. The CENP-A-targeting domain (CATD) of CENP-A specifically binds to HJURP, and this binding is conserved. However, the binding interface of CENP-A-HJURP is yet to be understood. Here, we identify the critical residues for chicken CENP-A or HJURP. The A59Q mutation in the α1-helix of chicken CENP-A causes CENP-A mis-incorporation and subsequent cell death, whereas the corresponding mutation in human CENP-A does not. We also find that W53 of HJURP, which is a contact site of A59 in CENP-A, is also essential in chicken cells. Our comprehensive analyses reveal that the affinities of HJURP to CATD differ between chickens and humans. However, the introduction of two arginine residues to the chicken HJURP αA-helix suppresses CENP-A mis-incorporation in chicken cells expressing CENP-A. Our data explain the mechanisms and evolution of CENP-A essentiality by the CENP-A-HJURP interaction.

摘要

着丝粒指定对于着丝粒至关重要，由伴侣蛋白 HJURP 介导。CENP-A 的着丝粒靶向结构域（CATD）特异性结合 HJURP，这种结合是保守的。然而，CENP-A-HJURP 的结合界面尚不清楚。在这里，我们确定了鸡 CENP-A 或 HJURP 的关键残基。鸡 CENP-A 的α1-螺旋中的 A59Q 突变导致 CENP-A 错误掺入，随后细胞死亡，而人 CENP-A 中的相应突变则不会。我们还发现 HJURP 的 W53 是 CENP-A 中 A59 的接触位点，在鸡细胞中也是必不可少的。我们的综合分析表明，鸡和人之间 HJURP 对 CATD 的亲和力不同。然而，在表达 CENP-A 的鸡细胞中引入两个精氨酸残基到鸡 HJURPαA-螺旋中，可以抑制 CENP-A 错误掺入。我们的数据通过 CENP-A-HJURP 相互作用解释了 CENP-A 必要性的机制和进化。