LOVASTATIN INSENSITIVE 1, a novel pentatricopeptide repeat protein, is a potential regulatory factor of isoprenoid biosynthesis in Arabidopsis
LOVASTATIN INSENSITIVE 1, a novel pentatricopeptide repeat protein, is a potential regulatory factor of isoprenoid biosynthesis in Arabidopsis
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DOI：
10.1093/pcp/pcm005
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发表时间：
2007-02-01
影响因子：
4.9
通讯作者：
Muranaka, Toshiya
中科院分区：
文献类型：
--
作者：
Kobayashi, Keiko;Suzuki, Masashi;Muranaka, Toshiya
高等植物类异戊二烯生物合成有两条代谢途径：胞质甲羟戊酸（MVA）途径和质体非甲羟戊酸（MEP）途径。尽管这两种途径是区室化的，但代谢流发生在它们之间。然而，很少有人知道的机制，调节这两个途径和代谢串扰。为了确定这样的调节机制，我们分离和表征了拟南芥T-DNA插入突变体洛伐他汀不敏感1（loi 1），这是耐洛伐他汀和异恶草酮，抑制剂MVA和MEP途径，分别。这些途径的主要产物，即甾醇和叶绿素的积累，分别受到洛伐他汀和异恶草酮的影响较小，在loi 1比在野生型。此外，3-羟基-3-甲基戊二酰辅酶A还原酶（HMGR）活性分析显示，洛伐他汀处理的loi 1 -1中的HMGR活性高于WT。我们认为loi 1 -1的洛伐他汀耐药表型来自HMGR的转录后上调。LOI 1基因编码一种新的五肽重复序列（PPR）蛋白。PPR蛋白被认为通过线粒体或质体中的转录后调节来调节细胞器基因组中编码的基因的表达。我们的研究结果表明，LOI 1被预测定位在线粒体中，并具有结合单链核酸的能力。我们的研究表明，线粒体RNA的转录后调控可能参与了MVA和MEP途径中的类异戊二烯生物合成。
Higher plants have two metabolic pathways for isoprenoid biosynthesis: the cytosolic mevalonate (MVA) pathway and the plastidal non-mevalonate (MEP) pathway. Despite the compartmentalization of these two pathways, metabolic flow occurs between them. However, little is known about the mechanisms that regulate the two pathways and the metabolic cross-talk. To identify such regulatory mechanisms, we isolated and characterized the Arabidopsis T-DNA insertion mutant lovastatin insensitive 1 (loi1), which is resistant to lovastatin and clomazone, inhibitors of the MVA and MEP pathways, respectively. The accumulation of the major products of these pathways, i.e. sterols and chlorophyll, was less affected by lovastatin and clomazone, respectively, in loi1 than in the wild type. Furthermore, the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) activity analysis showed higher activity of HMGR in loi1-1 treated with lovastatin than that in the WT. We consider that the lovastatin-resistant phenotype of loi1-1 was derived from this post-transcriptional up-regulation of HMGR. The LOI1 gene encodes a novel pentatricopeptide repeat (PPR) protein. PPR proteins are thought to regulate the expression of genes encoded in organelle genomes by post-transcriptional regulation in mitochondria or plastids. Our results demonstrate that LOI1 is predicted to localize in mitochondria and has the ability to bind single-stranded nucleic acids. Our investigation revealed that the post-transcriptional regulation of mitochondrial RNA may be involved in isoprenoid biosynthesis in both the MVA and MEP pathways.