Conserved, yet distinct: revisiting the roles of C core vacuole/endosome tethering (CORVET) and homotypic fusion and vacuole protein sorting (HOPS) complexes in plants

The spatially constrained nature of plant cells makes them highly reliant on targeted membrane vesicle trafficking, which sustains proper cellular function, tissue organization, and overall plant growth and development. These mechanisms are regulated by small GTPases, which function assembling tethering complexes and later serve as their effectors. Tethering factors facilitate the initial contact between the target membrane and incoming vesicles, thereby playing a pivotal role in vesicle targeting and fusion. This review focuses on two tethering complexes, the class C core vacuole/endosome tethering (CORVET) and the homotypic fusion and vacuole protein sorting (HOPS) tethering complex, which have been best studied in the model plant Arabidopsis thaliana. The activity of these complexes has been linked to the regulation of multivesicular endosomes with the vacuole membrane. However, recent reports propose additional functions for specific HOPS subunits regulating other fusion events. Despite these advances, our understanding of HOPS/CORVET function and regulation, including the input of small GTPases, remains incomplete. Thus, in this review, we emphasize the essential role of the HOPS/CORVET tethering complex in plant growth and development while identifying key gaps for future research.