Zooming into plant ubiquitin-mediated endocytosis

- Ub plays crucial roles in plant PM protein internalization and endosomal sorting.
- Ub-mediated endocytosis uses both monoUb and lysine-63 polyUb chains.
- Ub-binding proteins route ubiquitinated cargoes along the endocytic pathway.
- Plant-specific factors contribute to the ESCRT machinery and cargo trafficking.

Endocytosis in plants plays an essential role, not only for basic cellular functions but also for growth, development, and environmental responses. Over the past few years, ubiquitin emerged as a major signal triggering the removal of plasma membrane proteins from the cell surface and promoting their vacuolar targeting. Detailed genetic, biochemical and imaging studies have provided initial insights into the precise mechanisms and roles of ubiquitin-mediated endocytosis in plants. Here, we summarize the present state of knowledge about the machinery involved in plant ubiquitin-mediated endocytosis and how this is coordinated in time and space to control the internalization and the endosomal sorting of endocytosed proteins.

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