Mazeed Mohd, Singh Raghvendra, Kumar Pradeep, Roy Ankit, Raman Bakthisaran, Kruparani Shobha P, Sankaranarayanan Rajan
CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
Academy of Scientific and Innovative Research (AcSIR), CSIR-CCMB campus, Uppal Road, Hyderabad 500007, India.
Sci Adv. 2021 Feb 3;7(6). doi: 10.1126/sciadv.abe8890. Print 2021 Feb.
Streptophyte algae emerged as a land plant with adaptations that eventually led to terrestrialization. Land plants encounter a range of biotic and abiotic stresses that elicit anaerobic stress responses. Here, we show that acetaldehyde, a toxic metabolite of anaerobic stress, targets and generates ethyl adducts on aminoacyl-tRNA, a central component of the translation machinery. However, elongation factor thermo unstable (EF-Tu) safeguards l-aminoacyl-tRNA, but not d-aminoacyl-tRNA, from being modified by acetaldehyde. We identified a unique activity of archaeal-derived chiral proofreading module, d-aminoacyl-tRNA deacylase 2 (DTD2), that removes -ethyl adducts formed on d-aminoacyl-tRNAs (NEDATs). Thus, the study provides the molecular basis of ethanol and acetaldehyde hypersensitivity in DTD2 knockout plants. We uncovered an important gene transfer event from methanogenic archaea to the ancestor of land plants. While missing in other algal lineages, DTD2 is conserved from streptophyte algae to land plants, suggesting its role toward the emergence and evolution of land plants.
链形植物藻类进化成为陆地植物,其适应性变化最终导致了陆地化。陆地植物会遭遇一系列生物和非生物胁迫,从而引发厌氧胁迫反应。在此,我们表明,乙醛作为厌氧胁迫的一种有毒代谢产物,会作用于翻译机制的核心组成部分氨酰-tRNA,并在其上生成乙基加合物。然而,热不稳定延伸因子(EF-Tu)可保护L-氨酰-tRNA,而非D-氨酰-tRNA不被乙醛修饰。我们鉴定出了源自古菌的手性校对模块——D-氨酰-tRNA脱酰基酶2(DTD2)的一种独特活性,该活性可去除在D-氨酰-tRNA(NEDATs)上形成的N-乙基加合物。因此,这项研究提供了DTD2基因敲除植物中乙醇和乙醛超敏反应的分子基础。我们发现了从产甲烷古菌到陆地植物祖先的一个重要基因转移事件。虽然DTD2在其他藻类谱系中不存在,但从链形植物藻类到陆地植物它都是保守的,这表明了其在陆地植物出现和进化过程中的作用。