The ESCRT-I components VPS28A and VPS28B are essential for auxin-mediated plant development
The ESCRT-I components VPS28A and VPS28B are essential for auxin-mediated plant development
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ESCRT-I 组分 VPS28A 和 VPS28B 对于生长素介导的植物发育至关重要
DOI：
10.1111/tpj.15024
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发表时间：
2020-11-08
期刊：
影响因子：
7.2
通讯作者：
Cheng, Youfa
中科院分区：
文献类型：
--
作者：
Liu, Jianyang;Wang, Yanning;Cheng, Youfa
高度保守的内体转运复合物（ESCRT）途径在泛素化质膜蛋白的内体分选降解中起着关键作用。然而，植物中ESCRT机制的许多组件的功能仍然没有解决。在这里，我们表明，ESCRT-I亚基VPS 28 A和VPS 28 B是功能冗余的，需要在拟南芥胚胎发育。我们进行了pid基因增强子的筛选，pid基因在生长素信号传导和运输方面有缺陷。我们在pid 104（ncp 104）中分离到一个无子叶突变体，该突变体在pid背景下不能发育子叶。我们发现ncp 104是vps 28 a的一个独特的隐性功能获得性等位基因。VPS 28 A和VPS 28 B在胚胎发生过程中表达，并且蛋白质定位于trans-Golgi网络/早期内体和post-Golgi/内体隔室，与它们在内体分选和胚胎发生中的功能一致。vps 28 a和vps 28 b单突变体没有表现出明显的发育缺陷，但其双突变体表现出异常的细胞分裂模式，并在球形胚阶段被阻止。vps 28 a和vps 28 b双突变体表现出改变的生长素反应，破坏的PIN 1-GFP表达模式，以及在小的异常液泡中的异常PIN 1-GFP积累。ncp 104突变可能导致VPS 28 A蛋白变得不稳定和/或有毒。综上所述，我们的研究结果表明，ESCRT-I组分VPS 28 A和VPS 28 B冗余地在液泡形成，质膜蛋白的内体分选和生长素介导的植物发育中发挥重要作用。
The highly conserved endosomal sorting complex required for transport (ESCRT) pathway plays critical roles in endosomal sorting of ubiquitinated plasma membrane proteins for degradation. However, the functions of many components of the ESCRT machinery in plants remain unsolved. Here we show that the ESCRT-I subunits VPS28A and VPS28B are functionally redundant and required for embryonic development in Arabidopsis. We conducted a screen for genetic enhancers of pid, which is defective in auxin signaling and transport. We isolated a no--cotyledon in pid 104 (ncp104) mutant, which failed to develop cotyledons in a pid background. We discovered that ncp104 was a unique recessive gain-of-function allele of vps28a. VPS28A and VPS28B were expressed during embryogenesis and the proteins were localized to the trans-Golgi network/early endosome and post-Golgi/endosomal compartments, consistent with their functions in endosomal sorting and embryogenesis. The single vps28a and vps28b loss-of-function mutants did not display obvious developmental defects, but their double mutants showed abnormal cell division patterns and were arrested at the globular embryo stage. The vps28a vps28b double mutants showed altered auxin responses, disrupted PIN1-GFP expression patterns, and abnormal PIN1-GFP accumulation in small aberrant vacuoles. The ncp104 mutation may cause the VPS28A protein to become unstable and/or toxic. Taken together, our findings demonstrate that the ESCRT-I components VPS28A and VPS28B redundantly play essential roles in vacuole formation, endosomal sorting of plasma membrane proteins, and auxin-mediated plant development.