ER-phagy requires Lnp1, a protein that stabilizes rearrangements of the ER network

Significance The endoplasmic reticulum (ER) undergoes autophagy in response to starvation in a process utilizing Atg40, a cortical ER receptor that serves to recruit the machinery needed to assemble an autophagosome. Little is known about the components that work in conjunction with ER cargo receptors. Here we show that autophagy of the ER requires Lnp1, a protein that helps to maintain the structure of the ER by stabilizing rearrangements of the ER network. In the absence of Lnp1 or upon depolymerization of actin, Atg40 puncta fail to distribute to the cell interior, where the autophagy machinery resides, thus blocking incorporation of ER into autophagosomes. These studies show that the localization of Atg40 is critical for its function as a cargo receptor.