title: An ER-Localized SNARE Protein Is Exported in Specific COPII Vesicles for Autophagosome Biogenesis.
abstract: The de novo formation of autophagosomes for the targeting of cytosolic material to the vacuole/lysosome is upregulated upon starvation. How autophagosomes acquire membranes remains still unclear. Here, we report that, in yeast, the endoplasmic reticulum (ER)-localized Qa/t-SNARE Ufe1 has a role in autophagy. During starvation, Ufe1 is increasingly exported from the ER and targeted to intracellular sites that contain the autophagy markers Atg8 and Atg9. In addition, Ufe1 interacts with non-ER SNARE proteins implicated in autophagosome formation. Loss of Ufe1 function impairs autophagy and results in fewer and smaller autophagosomes. Unlike conventional cargo, the ER export of Ufe1 is significantly reduced in sec23-1 cells, which affects the coat protein (COP)II complex, already at the permissive temperature. Under the same conditions, sec23-1 cells are hypersensitive to starvation and deficient in autophagy. Our data suggest that ER membranes containing Ufe1 are delivered to sites of autophagosome formation in specific COPII vesicles.
authors.affiliation: Department of Genetics, University of Seville, Avenue Reina Mercedes, s/n, 41012 Seville, Spain.
authors.forename: Leticia
authors.initials: L
authors.lastname: Lemus
authors.affiliation: Centro de Investigación Tecnología e Innovación de la Universidad de Sevilla, Avenue Reina Mercedes, 41012 Seville, Spain.
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Ribas
authors.affiliation: Department of Genetics, University of Seville, Avenue Reina Mercedes, s/n, 41012 Seville, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Sikorska
authors.affiliation: Department of Genetics, University of Seville, Avenue Reina Mercedes, s/n, 41012 Seville, Spain. Electronic address: vgoder@us.es.
authors.forename: Veit
authors.initials: V
authors.lastname: Goder
mesh_terms: D001343:Autophagy; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D022181:COP-Coated Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D003470:Culture Media / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D015966:Gene Expression Regulation, Fungal; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009584:Nitrogen / Q000172:deficiency; D001678:Organelle Biogenesis; D010588:Phagosomes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D021381:Protein Transport; D050765:Qa-SNARE Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013696:Temperature; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure
chemical_list: C113757:ATG8 protein, S cerevisiae; C434065:ATG9 protein, S cerevisiae; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D003470:Culture Media; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D050765:Qa-SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; C103868:UFE1 protein, S cerevisiae; D009584:Nitrogen