Cao Shi-Kai, Liu Rui, Sayyed Aqib, Sun Feng, Song Ruolin, Wang Xiaomin, Xiu Zhihui, Li Xiaojie, Tan Bao-Cai
Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China.
Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, China.
Front Plant Sci. 2021 Aug 2;12:695249. doi: 10.3389/fpls.2021.695249. eCollection 2021.
In flowering plants, mitochondrial genes contain approximately 20-26 introns. Splicing of these introns is essential for mitochondrial gene expression and function. Recent studies have revealed that both nucleus- and mitochondrion-encoded factors are required for intron splicing, but the mechanism of splicing remains largely unknown. Elucidation of the mechanism necessitates a complete understanding of the splicing factors. Here, we report the identification of a regulator of chromosome condensation 1 (RCC1)-domain protein DEK47 that is required for mitochondrial intron splicing and seed development in maize. Loss of function in severely arrests embryo and endosperm development, resulting in a phenotype. DEK47 harbors seven RCC1 domains and is targeted to mitochondria. Null mutation of DEK47 causes a deficiency in the splicing of all four introns, abolishing the production of mature transcript and resulting in the disassembly and severely reduced activity of mitochondrial complex I. In response, the expression of the alternative oxidase is sharply increased in . These results indicate that is required for the splicing of all the introns in mitochondria, and essential for complex I assembly, and kernel development in maize.
在开花植物中，线粒体基因含有大约20 - 26个内含子。这些内含子的剪接对于线粒体基因的表达和功能至关重要。最近的研究表明，核编码因子和线粒体编码因子都是内含子剪接所必需的，但剪接机制在很大程度上仍不清楚。阐明该机制需要全面了解剪接因子。在这里，我们报告了在玉米中鉴定出一种染色体凝聚调节因子1（RCC1）结构域蛋白DEK47，它是线粒体内含子剪接和种子发育所必需的。功能丧失严重阻碍胚胎和胚乳发育，导致一种表型。DEK47含有七个RCC1结构域，并定位于线粒体。DEK47的无效突变导致所有四个内含子的剪接缺陷，消除了成熟转录本的产生，并导致线粒体复合体I的解体和活性严重降低。作为响应，交替氧化酶的表达在……中急剧增加。这些结果表明，DEK47是线粒体中所有内含子剪接所必需的，对复合体I组装和玉米籽粒发育至关重要。
