The gene for mitochondrial ribosomal protein S14 has been transferred to the nucleus in Arabidopsis thaliana
The gene for mitochondrial ribosomal protein S14 has been transferred to the nucleus in Arabidopsis thaliana
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DOI：
10.1007/s004380051068
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发表时间：
1999-08-01
期刊：
影响因子：
--
通讯作者：
Jordana, X
中科院分区：
文献类型：
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作者：
Figueroa, P;Gómez, I;Jordana, X
人们认为高等植物中遗传信息从线粒体到细胞核的转移仍在进行中。拟南芥线粒体基因组仅含有一个rps14假基因。在本文中，我们证明编码线粒体核糖体蛋白 S14 的功能基因已被易位至细胞核。这种基因转移是最近的进化事件，发生在十字花科植物中，可能是在拟南芥和甘蓝型油菜分化之后。 rps14 阅读框的 5' 延伸编码一个前序列，该前序列在体外将多肽靶向分离的线粒体，并在导入期间或导入后被切除。在直接连接的靶向前序列与线粒体衍生序列的连接处没有发现内含子。相比之下，90 bp 的内含子位于 3' 非编码区，通过剪接去除，得到 0.9 kb 的成熟 Poly(A)(+) mRNA。据我们所知，这是高等植物功能性转移基因中内含子位于该位置的首次报道，并且表明外显子改组可能涉及细胞核中表达所需元件的获取。讨论了该内含子在多腺苷酸化和基因表达增强中的假定作用。
The transfer of genetic information from the mitochondrion to the nucleus is thought to be still underway in higher plants. The mitochondrial genome of Arabidopsis thaliana contains only one rps14 pseudogene. In this paper we show that the functional gene encoding mitochondrial ribosomal protein S14 has been translocated to the nucleus. This gene transfer is a recent evolutionary event, which occurred within Cruciferae, probably after the divergence of Arabidopsis and Brassica napus. A 5' extension of the rps14 reading frame encodes a presequence which, in vitro, targets the polypeptide to isolated mitochondria and is cleaved off during or after import. No intron was found at the junction of the targeting presequence with the mitochondrially derived sequence, which are directly connected. By contrast, a 90-bp intron, which is removed by splicing to give a mature poly(A)(+) mRNA of 0.9 kb, is located in the 3' non-coding region. To our knowledge, this is the first report of an intron in such a position in a functional transferred gene in higher plants, and suggests that exon shuffling may have been involved in the acquisition of elements necessary for expression in the nucleus. Putative roles of this intron in polyadenylation and enhancement of gene expression are discussed.