蛋白质 N-豆蔻酰化在人线粒体复合物 I 辅助亚基 NDUFB7 的线粒体定位中起着关键作用。
Protein N-myristoylation plays a critical role in the mitochondrial localization of human mitochondrial complex I accessory subunit NDUFB7.
机构信息
Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan.
Department of Cell Chemistry, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Okayama, Japan.
出版信息
Sci Rep. 2023 Dec 27;13(1):22991. doi: 10.1038/s41598-023-50390-z.
The present study examined human N-myristoylated proteins that specifically localize to mitochondria among the 1,705 human genes listed in MitoProteome, a mitochondrial protein database. We herein employed a strategy utilizing cellular metabolic labeling with a bioorthogonal myristic acid analog in transfected COS-1 cells established in our previous studies. Four proteins, DMAC1, HCCS, NDUFB7, and PLGRKT, were identified as N-myristoylated proteins that specifically localize to mitochondria. Among these proteins, DMAC1 and NDUFB7 play critical roles in the assembly of complex I of the mitochondrial respiratory chain. DMAC1 functions as an assembly factor, and NDUFB7 is an accessory subunit of complex I. An analysis of the intracellular localization of non-myristoylatable G2A mutants revealed that protein N-myristoylation occurring on NDUFB7 was important for the mitochondrial localization of this protein. Furthermore, an analysis of the role of the CHCH domain in NDUFB7 using Cys to Ser mutants revealed that it was essential for the mitochondrial localization of NDUFB7. Therefore, the present results showed that NDUFB7, a vital component of human mitochondrial complex I, was N-myristoylated, and protein N-myrisotylation and the CHCH domain were both indispensable for the specific targeting and localization of NDUFB7 to mitochondria.
本研究在 MitoProteome(线粒体蛋白质数据库)中列出的 1705 个人类基因中,筛选出能够特异性定位于线粒体的人 N-豆蔻酰化蛋白。在本研究中,我们采用了在之前的研究中建立的经转染的 COS-1 细胞中利用生物正交豆蔻酸类似物进行细胞代谢标记的策略。鉴定出 4 种蛋白(DMAC1、HCCS、NDUFB7 和 PLGRKT)为特异性定位于线粒体的 N-豆蔻酰化蛋白。在这些蛋白中,DMAC1 和 NDUFB7 在组装线粒体呼吸链复合物 I 中发挥关键作用。DMAC1 作为组装因子发挥作用,而 NDUFB7 是复合物 I 的辅助亚基。对非豆蔻酰化 G2A 突变体的细胞内定位分析表明,发生在 NDUFB7 上的蛋白 N-豆蔻酰化对该蛋白的线粒体定位很重要。此外,使用 Cys 到 Ser 突变体对 NDUFB7 中的 CHCH 结构域的作用进行分析表明,该结构域对于 NDUFB7 的线粒体定位是必需的。因此,本研究结果表明,作为人类线粒体复合物 I 的重要组成部分的 NDUFB7 发生了 N-豆蔻酰化,而蛋白 N-豆蔻酰化和 CHCH 结构域对于 NDUFB7 特异性靶向和定位于线粒体都是不可或缺的。