title: ER-phagy mediates selective degradation of endoplasmic reticulum independently of the core autophagy machinery.
abstract: Selective autophagy of damaged or redundant organelles is an important mechanism for maintaining cell homeostasis. We found previously that endoplasmic reticulum (ER) stress in the yeast Saccharomyces cerevisiae causes massive ER expansion and triggers the formation of large ER whorls. Here, we show that stress-induced ER whorls are selectively taken up into the vacuole, the yeast lysosome, by a process termed ER-phagy. Import into the vacuole does not involve autophagosomes but occurs through invagination of the vacuolar membrane, indicating that ER-phagy is topologically equivalent to microautophagy. Even so, ER-phagy requires neither the core autophagy machinery nor several other proteins specifically implicated in microautophagy. Thus, autophagy of ER whorls represents a distinct type of organelle-selective autophagy. Finally, we provide evidence that ER-phagy degrades excess ER membrane, suggesting that it contributes to cell homeostasis by controlling organelle size.
authors: Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California San Francisco, 600 16th Street, San Francisco, CA 94158, USA s.schuck@zmbh.uni-heidelberg.de.
authors: Sebastian
authors: S
authors: Schuck
authors: Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California San Francisco, 600 16th Street, San Francisco, CA 94158, USA.
authors: Ciara M
authors: CM
authors: Gallagher
authors: Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California San Francisco, 600 16th Street, San Francisco, CA 94158, USA.
authors: Peter
authors: P
authors: Walter
mesh_terms: D001343:Autophagy; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D059865:Endoplasmic Reticulum Stress; D008247:Lysosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism
chemical_list: D029701:Saccharomyces cerevisiae Proteins
keywords: Autophagy; Endoplasmic reticulum; Stress response