Coming of age of plant amphisomes

In metazoans, autophagosomes fuse with late endosomes (LEs)/multivesicular bodies (MVBs) to form a hybrid organelle known as an amphisome. Subsequently upon fusion with lysosomes the contents of amphisomes are degraded. While the formation of metazoan amphisomes has been well established, it has remained an open question whether amphisomes form and deliver their cargo to the central vacuole for degradation in plant cells. In this mini review, we provide an update on recent discoveries in the field of plant autophagy that demonstrate the formation of amphisome-like organelles that are generated through several distinct autophagosome/MVB fusion pathways.<b>Abbreviations</b>: CFS1: FYVE domain-containing protein; CORVET: core vacuole/endosome tethering; ER: endoplasmic reticulum; ESCRT: endosomal sorting complex required for transport; FYVE: Fab1p, YOTB, Vac1p, and EEA1; FREE1: FYVE domain protein required for endosomal sorting; HOPS: homotypic fusion and protein sorting; LEs: late endosomes; MVBs: multivesicular bodies; PtdIns3P: phosphatidylinositol-3-phosphate; SNAREs: soluble NSF attachment protein receptors; VAPVs: VPS41-associated phagic vacuoles.