Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique Unité Mixte de Recherche 5004, Institut de Biologie Intégrative des Plantes, Montpellier, France.
Plant Signal Behav. 2011 Oct;6(10):1597-9. doi: 10.4161/psb.6.10.17134. Epub 2011 Oct 1.
In plants, the tight regulation of plasma membrane transporters is essential to maintain nutrient homeostasis. The mechanisms controlling the abundance of transporters, and other integral plasma membrane proteins, now come to light. Ubiquitination appears as a major signal initiating cargo endocytosis and sorting into multivesicular bodies prior to degradation in the vacuole. We have indeed demonstrated that the root iron transporter IRT1 is subjected to ubiquitin-dependent trafficking in root epidermal cells. This control is crucial to keep IRT1 levels at the cell surface low and to cope with the toxicity associated with other readily available metal substrates of IRT1. Our work combined with recent report on the BOR1 boron transporter establishes ubiquitination as a conserved mechanism of plasma membrane protein trafficking in plants, and highlights its importance for plant nutrition.
在植物中，质膜转运蛋白的严密调控对于维持养分稳态至关重要。目前，控制转运蛋白和其他完整质膜蛋白丰度的机制逐渐明朗。泛素化似乎是启动货物内吞作用以及分拣到液泡中进行降解的主要信号。我们确实证明，根铁转运蛋白 IRT1 受到根表皮细胞中泛素依赖性运输的调控。这种控制对于保持 IRT1 在细胞表面的低水平以及应对与 IRT1 其他易获得的金属底物相关的毒性至关重要。我们的工作与最近关于 BOR1 硼转运蛋白的报告相结合，确立了泛素化是植物质膜蛋白运输的一种保守机制，并强调了其对植物营养的重要性。
