ABA, porphyrins and plant TSPO-related protein
ABA, porphyrins and plant TSPO-related protein
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DOI：
10.4161/psb.4.11.9796
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发表时间：
2009-01-01
影响因子：
2.9
通讯作者：
Batoko, Henri
中科院分区：
文献类型：
--
作者：
Guillaumot, Damien;Guillon, Stephanie;Batoko, Henri
我们意外地发现，AtTSPO（拟南芥 TSPO 相关蛋白）是植物细胞中的内质网和高尔基体定位的膜蛋白。 1 这种定位与哺乳动物 18-kDa 易位蛋白（至少对于研究最多的异构体 18-kDa TSPO）的定位形成对比，后者是一种线粒体外膜蛋白（参考文献 2 中进行了综述）。尽管 18-kDa TSPO 的潜在功能已得到充分记录，主要涉及线粒体生理学，2 及其作为药物靶点的兴趣正在探索，3 TSPO 相关蛋白在植物生长和发育中的作用仍有待明确。 AtTSPO 在干燥种子中表达，并且可以通过渗透压和盐胁迫或脱落酸 (ABA) 处理在营养组织中诱导。此外，研究表明，ABA 依赖性诱导是短暂的，并且通过 5-氨基乙酰丙酸 (ALA) 喂养促进四吡咯生物合成增强了 AtTSPO 的下调，这表明固有的翻译后调节机制也涉及 ABA 和可能的卟啉。我们提供了额外的证据表明 ABA 可以帮助稳定 AtTSPO 的组成型表达，并且 ALA 喂养敲除突变种子会导致显着的发芽延迟。在这里，我们讨论 ABA 和四吡咯在 AtTSPO 表达和翻译后调控中可能存在的联系。
We have shown that, unexpectedly, AtTSPO (Arabidopsis thaliana TSPO-related protein) is an endoplasmic reticulum and Golgi-localized membrane protein in plant cells. 1 This localization contrasts with that of mammalian 18-kDa translocator protein (at least for the mostly studied isoform, 18-kDa TSPO), a mitochondrial outer membrane protein (reviewed in ref. 2). Whereas the potential functions of 18-kDa TSPO are well documented, involved mainly in mitochondrial physiology, 2 and its interest as a drug target is being explored, 3 the roles of TSPO-related proteins in plant growth and development are yet to be specified. AtTSPO is expressed in dry seeds and can be induced in vegetative tissues by osmotic and salt stress or abscisic acid (ABA) treatment. Moreover, it was shown that the ABA-dependent induction is transient, and that boosting tetrapyrroles biosynthesis through 5-aminolevulinic acid (ALA) feeding enhanced downregulation of AtTSPO, suggesting an inherent post-translational regulation mechanism also involving ABA and likely porphyrins. We present additional evidence that ABA can help stabilize constitutively expressed AtTSPO and that ALA feeding to knockout mutant seeds, induces substantial germination delay. Here we discuss the possible link between ABA and tetrapyrroles in AtTSPO expression and posttranslational regulation.