PLEIOTROPIC REGULATORY LOCUS 1 (PRL1) Integrates the Regulation of Sugar Responses with Isoprenoid Metabolism in Arabidopsis
PLEIOTROPIC REGULATORY LOCUS 1 (PRL1) Integrates the Regulation of Sugar Responses with Isoprenoid Metabolism in Arabidopsis
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DOI：
10.1093/mp/ssp100
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发表时间：
2010-01-01
期刊：
影响因子：
27.5
通讯作者：
Rodriguez-Concepcion, Manuel
中科院分区：
文献类型：
--
作者：
Flores-Perez, Ursula;Perez-Gila, Jordi;Rodriguez-Concepcion, Manuel
类异戊二烯在植物细胞中的生物合成是由甲羟戊酸（MVA）途径在细胞质中产生的前体和4-磷酸甲酯（MEP）途径在质体中产生的前体来进行的，但对协调这两种途径的机制知之甚少。糖信号对拟南芥中这种协调的重要性的证据在这里提供的突变体的表征显示增加的积累MEP衍生的类异戊二烯产品（叶绿素和类胡萝卜素），而不改变相关的MEP途径转录本，蛋白质，或酶活性的水平。该突变体被发现是PRL 1（多效调节基因座1）的一个新的功能丧失等位基因，PRL 1是一种编码保守WD蛋白的基因，其功能是糖、应激和激素反应的全局调节剂，部分通过抑制SNF 1相关蛋白激酶（SnRK 1）。与报道的SnRK 1激酶在MVA途径的主要调节酶（羟甲基戊二酰辅酶A还原酶）的磷酸化和失活中的作用一致，其活性而不是转录物或蛋白质水平在prl 1幼苗中降低。然而，积累的MVA衍生的最终产品（甾醇）是不变的突变体幼苗。补充蔗糖对野生型幼苗表型模仿prl 1突变体的类异戊二烯代谢，这表明观察到的类异戊二烯表型是由于prl 1突变体中糖积累增加所致。总之，PRL 1似乎协调类异戊二烯代谢与糖，激素和应激反应。
The biosynthesis of isoprenoids in plant cells occurs from precursors produced in the cytosol by the mevalonate (MVA) pathway and in the plastid by the methylerythritol 4-phosphate (MEP) pathway, but little is known about the mechanisms coordinating both pathways. Evidence of the importance of sugar signaling for such coordination in Arabidopsis thaliana is provided here by the characterization of a mutant showing an increased accumulation of MEP-derived isoprenoid products (chlorophylls and carotenoids) without changes in the levels of relevant MEP pathway transcripts, proteins, or enzyme activities. This mutant was found to be a new loss-of-function allele of PRL1 (Pleiotropic Regulatory Locus 1), a gene encoding a conserved WD-protein that functions as a global regulator of sugar, stress, and hormone responses, in part by inhibition of SNF1-related protein kinases (SnRK1). Consistent with the reported role of SnRK1 kinases in the phosphorylation and inactivation of the main regulatory enzyme of the MVA pathway (hydroxymethylglutaryl coenzyme-A reductase), its activity but not transcript or protein levels was reduced in prl1 seedlings. However, the accumulation of MVA-derived end products (sterols) was unaltered in mutant seedlings. Sucrose supplementation to wild-type seedlings phenocopied the prl1 mutation in terms of isoprenoid metabolism, suggesting that the observed isoprenoid phenotypes result from the increased sugar accumulation in the prl1 mutant. In summary, PRL1 appears to coordinate isoprenoid metabolism with sugar, hormone, and stress responses.