拟南芥HOPS复合体亚基VPS41定位于无膜结构参与调控植物液泡运输

The HOPS complex is a conserved, multi-subunit tethering complex in eukaryotic cells. In yeast and mammalian cells, the HOPS subunit VPS41 is recruited to late endosomes after Rab7 activation and is essential for vacuole fusion. However, whether VPS41 plays conserved roles in plants is not clear. Here, we demonstrate that in model plant Arabidopsis, VPS41 localizes to distinct membrane-less puncta in root cells in addition to its reported localization at tonoplast. The formation of membrane-less puncta does not rely on the known upstream regulators but depends on VPS41 self-interaction and is essential for plant early development. Genetic evidence indicates that VPS41 is required for both homotypic vacuole fusion and cargo sorting from the AP-3, Rab5, and Golgi-independent pathways but is dispensable for the Rab7 cargo INT1. We also show that VPS41 has HOPS independent functions in vacuolar transport. Taken together, our findings indicate that Arabidopsis VPS41 is a unique subunit of the HOPS complex that carries out plant-specific roles in both vacuolar transport and developmental regulation.