University of Tübingen, Center for Plant Molecular Biology (ZMBP), 72076 Tübingen, Germany.
Faculty of Biology & Biotechnology, Ruhr-University Bochum, 44780 Bochum, Germany.
Essays Biochem. 2022 Aug 5;66(2):189-206. doi: 10.1042/EBC20210063.
Plant immunity is antagonized by pathogenic effectors during interactions with bacteria, viruses or oomycetes. These effectors target core plant processes to promote infection. One such core plant process is autophagy, a conserved proteolytic pathway involved in ensuring cellular homeostasis. It involves the formation of autophagosomes around proteins destined for autophagic degradation. Many cellular components from organelles, aggregates, inactive or misfolded proteins have been found to be degraded via autophagy. Increasing evidence points to a high degree of specificity during the targeting of these components, strengthening the idea of selective autophagy. Selective autophagy receptors bridge the gap between target proteins and the forming autophagosome. To achieve this, the receptors are able to recognize specifically their target proteins in a ubiquitin-dependent or -independent manner, and to bind to ATG8 via canonical or non-canonical ATG8-interacting motifs. Some receptors have also been shown to require oligomerization to achieve their function in autophagic degradation. We summarize the recent advances in the role of selective autophagy in plant immunity and highlight NBR1 as a key player. However, not many selective autophagy receptors, especially those functioning in immunity, have been characterized in plants. We propose an in silico approach to identify novel receptors, by screening the Arabidopsis proteome for proteins containing features theoretically needed for a selective autophagy receptor. To corroborate these data, the transcript levels of these proteins during immune response are also investigated using public databases. We further highlight the novel perspectives and applications introduced by immunity-related selective autophagy studies, demonstrating its importance in research.
植物在与细菌、病毒或卵菌相互作用时会受到病原体效应子的拮抗。这些效应子针对核心植物过程以促进感染。核心植物过程之一是自噬，这是一种保守的蛋白水解途径，参与确保细胞内的平衡。它涉及到在蛋白质周围形成自噬体，这些蛋白质注定要进行自噬降解。许多来自细胞器、聚集体、失活或错误折叠的蛋白质的细胞成分都被发现通过自噬来降解。越来越多的证据表明，在这些成分的靶向过程中具有高度的特异性，这加强了选择性自噬的观点。选择性自噬受体在靶蛋白和正在形成的自噬体之间架起了桥梁。为了实现这一点，受体能够以泛素依赖或非依赖的方式特异性识别其靶蛋白，并通过经典或非经典的 ATG8 相互作用基序与 ATG8 结合。一些受体也被证明需要寡聚化才能在自噬降解中发挥其功能。我们总结了选择性自噬在植物免疫中的作用的最新进展，并强调 NBR1 是一个关键的参与者。然而，在植物中，被描述的选择性自噬受体，特别是那些在免疫中起作用的受体并不多。我们提出了一种基于计算的方法，通过筛选拟南芥蛋白质组中理论上需要的选择性自噬受体的特征来识别新的受体。为了证实这些数据，还使用公共数据库研究了这些蛋白质在免疫反应期间的转录水平。我们进一步强调了免疫相关选择性自噬研究带来的新视角和应用，证明了它在研究中的重要性。
