Chen Liang, Su Ze-Zhuo, Huang Li, Xia Fan-Nv, Qi Hua, Xie Li-Juan, Xiao Shi, Chen Qin-Fang
State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen UniversityGuangzhou, China.
College of Life Sciences, South China Agricultural UniversityGuangzhou, China.
Front Plant Sci. 2017 Jul 10;8:1201. doi: 10.3389/fpls.2017.01201. eCollection 2017.
Autophagy is a highly conserved system in eukaryotes for the bulk degradation and recycling of intracellular components. Autophagy is involved in many physiological processes including development, senescence, and responses to abiotic and biotic stress. The adenosine 5'-monophosphate (AMP)-activated protein kinase AMPK positively regulates autophagy in mammals; however, the potential function of AMPK in plant autophagy remains largely unknown. Here, we identified KIN10, a plant ortholog of the mammalian AMPK, as a positive regulator of plant autophagy and showed that it acts by affecting the phosphorylation of ATG1 (AUTOPHAGY-RELATED GENE 1) proteins in . Transgenic lines overexpressing () showed delays in leaf senescence, and increased tolerance to nutrient starvation, these phenotypes required a functional autophagy pathway. Consistent with KIN10 having a potential role in autophagy, the nutrient starvation-induced formation of autophagosomes and cleavage of GFP-ATG8e were accelerated in the lines compared to the wild type. Moreover, the lines were less sensitive to drought and hypoxia treatments, compared with wild type. Carbon starvation enhanced the level of phosphorylated YFP-ATG1a in the lines compared to that of wild type. Together, these findings suggest that KIN10 is involved in positive regulation of autophagy, possibly by affecting the phosphorylation of ATG1s in .
自噬是真核生物中一种高度保守的系统,用于细胞内成分的大量降解和循环利用。自噬参与许多生理过程,包括发育、衰老以及对非生物和生物胁迫的反应。腺苷5'-单磷酸(AMP)激活的蛋白激酶AMPK在哺乳动物中正向调节自噬;然而,AMPK在植物自噬中的潜在功能仍 largely unknown。在这里,我们鉴定出KIN10,它是哺乳动物AMPK在植物中的直系同源物,是植物自噬的正向调节因子,并表明它通过影响拟南芥中ATG1(自噬相关基因1)蛋白的磷酸化发挥作用。过表达KIN10的转基因拟南芥品系表现出叶片衰老延迟,对营养饥饿的耐受性增强,这些表型需要功能性自噬途径。与KIN10在自噬中具有潜在作用一致,与野生型相比,营养饥饿诱导的自噬体形成和GFP-ATG8e的切割在KIN10过表达品系中加速。此外,与野生型相比,KIN10过表达品系对干旱和缺氧处理不太敏感。与野生型相比,碳饥饿增强了KIN10过表达品系中磷酸化YFP-ATG1a的水平。总之,这些发现表明KIN10可能通过影响拟南芥中ATG1的磷酸化参与自噬的正向调节。