LAUSR

Plant cells contain two types of vacuoles, the lytic vacuole and the protein storage vacuole. Lytic vacuoles (LVs) are present in vegetative cells, whereas protein storage vacuoles (PSVs) are found in seed cells. The physiological functions of the two vacuole types differ. Newly synthesized proteins must be transported to these vacuoles via protein trafficking through the endomembrane system for them to function. Recently, significant advances have been made in elucidating the molecular mechanisms of protein trafficking to these organelles. Despite these advances, the relationship between the trafficking mechanisms in LV and PSVs remains unclear. Some aspects of the trafficking mechanisms are common to both organelles, but certain aspects are specific to trafficking to either LV or PSVs. In this review, we summarize recent findings on the components involved in protein trafficking to both LV and PSVs and compare them to examine the extent of overlap in the trafficking mechanisms. In addition, we discuss the interconnection between the LV and PSVs in protein trafficking machinery and the implication in the identity of these organelles.