The Arabidopsis EH proteins (AtEH1/Pan1 and AtEH2/Pan1) are components of the endocytic TPLATE complex (TPC) which is essential for endocytosis. Both proteins are homologues of the yeast ARP2/3 complex activator, Pan1p. Here, we show that these proteins are also involved in actin cytoskeleton regulated autophagy. Both AtEH/Pan1 proteins localise to the plasma membrane and autophagosomes. Upon induction of autophagy, AtEH/Pan1 proteins recruit TPC and AP-2 subunits, clathrin, actin and ARP2/3 proteins to autophagosomes. Increased expression of AtEH/Pan1 proteins boosts autophagosome formation, suggesting independent and redundant pathways for actin-mediated autophagy in plants. Moreover, AtEHs/Pan1-regulated autophagosomes associate with ER-PM contact sites (EPCS) where AtEH1/Pan1 interacts with VAP27-1. Knock-down expression of either AtEH1/Pan1 or VAP27-1 makes plants more susceptible to nutrient depleted conditions, indicating that the autophagy pathway is perturbed. In conclusion, we identify the existence of an autophagy-dependent pathway in plants to degrade endocytic components, starting at the EPCS through the interaction among AtEH/Pan1, actin cytoskeleton and the EPCS resident protein VAP27-1.
- MeSH
- Actins metabolism MeSH
- Arabidopsis metabolism ultrastructure MeSH
- Autophagy MeSH
- Autophagosomes metabolism ultrastructure MeSH
- Models, Biological MeSH
- Cell Membrane metabolism ultrastructure MeSH
- Endocytosis * MeSH
- Endoplasmic Reticulum metabolism ultrastructure MeSH
- Phylogeny MeSH
- Actin-Related Protein 2-3 Complex metabolism MeSH
- Actin Cytoskeleton metabolism MeSH
- Microfilament Proteins metabolism MeSH
- Arabidopsis Proteins metabolism MeSH
- Saccharomyces cerevisiae Proteins metabolism MeSH
- Protein Binding MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH