Department of Landscape and Horticulture, Ecology College, Lishui University, Lishui 323000, Zhejiang, China.
Department of Botany and Plant Pathology and Purdue Center for Plant Biology, 915 W. State Street, Purdue University, West Lafayette, IN 47907-2054, USA.
Cells. 2020 Nov 30;9(12):2562. doi: 10.3390/cells9122562.
Selective autophagy is a highly regulated degradation pathway for the removal of specific damaged or unwanted cellular components and organelles such as protein aggregates. Cargo selectivity in selective autophagy relies on the action of cargo receptors and adaptors. In mammalian cells, two structurally related proteins p62 and NBR1 act as cargo receptors for selective autophagy of ubiquitinated proteins including aggregation-prone proteins in aggrephagy. Plant NBR1 is the structural and functional homolog of mammalian p62 and NBR1. Since its first reports almost ten years ago, plant NBR1 has been well established to function as a cargo receptor for selective autophagy of stress-induced protein aggregates and play an important role in plant responses to a broad spectrum of stress conditions including heat, salt and drought. Over the past several years, important progress has been made in the discovery of specific cargo proteins of plant NBR1 and their roles in the regulation of plant heat stress memory, plant-viral interaction and special protein secretion. There is also new evidence for a possible role of NBR1 in stress-induced pexophagy, sulfur nutrient responses and abscisic acid signaling. In this review, we summarize these progresses and discuss the potential significance of NBR1-mediated selective autophagy in broad plant responses to both biotic and abiotic stresses.
选择性自噬是一种高度调控的降解途径，用于去除特定的受损或不需要的细胞成分和细胞器，如蛋白质聚集体。选择性自噬中的货物选择性依赖于货物受体和衔接蛋白的作用。在哺乳动物细胞中，两种结构相关的蛋白质 p62 和 NBR1 作为泛素化蛋白包括聚集倾向蛋白在自噬中的货物受体起作用。植物 NBR1 是哺乳动物 p62 和 NBR1 的结构和功能同源物。自近十年前首次报道以来，植物 NBR1 已被很好地确立为应激诱导蛋白聚集体选择性自噬的货物受体，并在植物对包括热、盐和干旱在内的广泛胁迫条件的反应中发挥重要作用。在过去的几年中，在发现植物 NBR1 的特定货物蛋白及其在植物热应激记忆、植物-病毒相互作用和特殊蛋白分泌调控中的作用方面取得了重要进展。也有新的证据表明 NBR1 可能在应激诱导的过氧化物酶体自噬、硫营养响应和脱落酸信号转导中发挥作用。在这篇综述中，我们总结了这些进展，并讨论了 NBR1 介导的选择性自噬在植物对生物和非生物胁迫的广泛反应中的潜在意义。
