Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, Texas 76203.
Departments of Biology, and Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599.
Plant Physiol. 2020 Sep;184(1):459-477. doi: 10.1104/pp.19.01552. Epub 2020 Jul 14.
In animals, several long-chain -acylethanolamines (NAEs) have been identified as endocannabinoids and are autocrine signals that operate through cell surface G-protein-coupled cannabinoid receptors. Despite the occurrence of NAEs in land plants, including nonvascular plants, their precise signaling properties and molecular targets are not well defined. Here we show that the activity of -linolenoylethanolamine (NAE 18:3) requires an intact G-protein complex. Specifically, genetic ablation of the Gβγ dimer or loss of the full set of atypical Gα subunits strongly attenuates an NAE-18:3-induced degreening of cotyledons in Arabidopsis () seedlings. This effect involves, at least in part, transcriptional regulation of chlorophyll biosynthesis and catabolism genes. In addition, there is feedforward transcriptional control of G-protein signaling components and G-protein interactors. These results are consistent with NAE 18:3 being a lipid signaling molecule in plants with a requirement for G-proteins to mediate signal transduction, a situation similar, but not identical, to the action of NAE endocannabinoids in animal systems.
在动物中，已经鉴定出几种长链酰基乙醇胺 (NAE) 作为内源性大麻素，是通过细胞表面 G 蛋白偶联大麻素受体起作用的自体信号。尽管 NAE 存在于陆地植物中，包括非维管束植物，但它们的确切信号特性和分子靶标尚未明确界定。在这里，我们表明 -linolenoylethanolamine (NAE 18:3) 的活性需要完整的 G 蛋白复合物。具体来说，Gβγ 二聚体的遗传缺失或全套非典型 Gα 亚基的缺失强烈减弱了拟南芥 () 幼苗中 NAE-18:3 诱导的子叶褪绿。这种效应至少部分涉及叶绿素生物合成和分解代谢基因的转录调控。此外，G 蛋白信号成分和 G 蛋白相互作用因子存在正向转录调控。这些结果表明，NAE 18:3 是植物中的一种脂质信号分子，需要 G 蛋白来介导信号转导，这种情况类似于但不完全等同于动物系统中 NAE 内源性大麻素的作用。
