Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Sevilla, Avda. Américo Vespucio, Sevilla, Spain.
Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, Paris, France.
J Exp Bot. 2021 Apr 13;72(9):3340-3351. doi: 10.1093/jxb/erab063.
Autophagy is a highly conserved degradative pathway that ensures cellular homeostasis through the removal of damaged or useless intracellular components including proteins, membranes, or even entire organelles. A main hallmark of autophagy is the biogenesis of autophagosomes, double-membrane vesicles that engulf and transport to the vacuole the material to be degraded and recycled. The formation of autophagosomes responds to integrated signals produced as a consequence of metabolic reactions or different types of stress and is mediated by the coordinated action of core autophagy-related (ATG) proteins. ATG4 is a key Cys-protease with a dual function in both ATG8 lipidation and free ATG8 recycling whose balance is crucial for proper biogenesis of the autophagosome. ATG4 is conserved in the green lineage, and its regulation by different post-translational modifications has been reported in the model systems Chlamydomonas reinhardtii and Arabidopsis. In this review, we discuss the major role of ATG4 in the integration of stress and redox signals that regulate autophagy in algae and plants.
自噬是一种高度保守的降解途径，通过清除受损或无用的细胞内成分，包括蛋白质、膜甚至整个细胞器，来确保细胞内的稳态。自噬的一个主要标志是自噬体的生物发生，自噬体是双层膜泡，可吞噬和运输待降解和再循环的物质到液泡中。自噬体的形成响应于代谢反应或不同类型的应激产生的综合信号，并通过核心自噬相关（ATG）蛋白的协调作用来介导。ATG4 是一种关键的半胱氨酸蛋白酶，在 ATG8 脂质化和游离 ATG8 再循环中具有双重功能，其平衡对于自噬体的正确生物发生至关重要。ATG4 在绿色谱系中是保守的，其在模式系统莱茵衣藻和拟南芥中的不同翻译后修饰的调节已经有报道。在这篇综述中，我们讨论了 ATG4 在整合应激和氧化还原信号中的主要作用，这些信号调节藻类和植物中的自噬。
