title: Ole1, fatty acid desaturase, is required for Atg9 delivery and isolation membrane expansion during autophagy in Saccharomyces cerevisiae.
abstract: Macroautophagy, a major degradation pathway of cytoplasmic components, is carried out through formation of a double-membrane structure, the autophagosome. Although the involvement of specific lipid species in the formation process remains largely obscure, we recently showed that mono-unsaturated fatty acids (MUFA) generated by stearoyl-CoA desaturase 1 (SCD1) are required for autophagosome formation in mammalian cells. To obtain further insight into the role of MUFA in autophagy, in this study we analyzed the autophagic phenotypes of the yeast mutant of OLE1, an orthologue of SCD1. Δole1 cells were defective in nitrogen starvation-induced autophagy, and the Cvt pathway, when oleic acid was not supplied. Defects in elongation of the isolation membrane led to a defect in autophagosome formation. In the absence of Ole1, the transmembrane protein Atg9 was not able to reach the pre-autophagosomal structure (PAS), the site of autophagosome formation. Thus, autophagosome formation requires Ole1 during the delivery of Atg9 to the PAS/autophagosome from its cellular reservoir.
authors.affiliation: Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829, Japan.|Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Ogasawara
authors.affiliation: Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Kira
authors.affiliation: Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Mukai
authors.affiliation: Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan a_yamamoto@nagahama-i-bio.ac.jp takenoda@dent.osaka-u.ac.jp.|Graduate school of Frontier Bioscience, Osaka University, 1-8 Yamadaoka, Suita, Japan.
authors.forename: Takeshi
authors.identifier: http://orcid.org/0000-0003-3581-7961
authors.initials: T
authors.lastname: Noda
authors.affiliation: Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829, Japan a_yamamoto@nagahama-i-bio.ac.jp takenoda@dent.osaka-u.ac.jp.
authors.forename: Akitsugu
authors.initials: A
authors.lastname: Yamamoto
keywords: Autophagy; Fatty acid monodesaturation; OLE1; Unsaturated fatty acid