2018 journal article

Phosphoinositides control the localization of HOPS subunit VPS41, which together with VPS33 mediates vacuole fusion in plants

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 115(35), EB305–EB314.

author keywords: Arabidopsis; vacuole fusion; HOPS; SNARE; phosphoinositides
MeSH headings : Arabidopsis / genetics; Arabidopsis / metabolism; Arabidopsis Proteins / genetics; Arabidopsis Proteins / metabolism; Membrane Fusion / physiology; Membrane Proteins / genetics; Membrane Proteins / metabolism; Phosphatidylinositol Phosphates / genetics; Phosphatidylinositol Phosphates / metabolism; Vacuoles / genetics; Vacuoles / metabolism; Vesicular Transport Proteins / genetics; Vesicular Transport Proteins / metabolism
TL;DR: It is shown that Arabidopsis HOPS subunits VPS33 and VPS41 accumulate in late endosomes and that VPS 41, but not VPS 33, accumulates in the tonoplast via a wortmannin-sensitive process, and that HOPS–SNARE interactions at the initial stage are similar to other eukaryotes. (via Semantic Scholar)
Source: Web Of Science
Added: November 7, 2018

Significance Plant vacuoles are essential organelles and occupy up to 90% of the cell volume. Their roles include regulation of stomata movements, protein storage in seeds, gravity sensing, and ion homeostasis. Vacuole or lysosome fusion in eukaryotes is mediated by two multisubunit complexes, SNARE and homotypic fusion and vacuolar protein sorting (HOPS), but only the SNARE complex is well characterized in plants. Here, we show that, similar to other eukaryotes, HOPS mediates vacuole fusion in plants by interaction with SNAREs and that the HOPS subunit VPS33 and the SNARE protein SYP22 display the sites for interaction between these complexes. In contrast to other eukaryotes, however, plant HOPS recruitment to liposomes is inhibited by phosphoinositides, which appear to define strict rules for regulating fusion and fragmentation of dynamic vacuoles.