タナベ　ケンジ   Tanabe Kenji   田邊　賢司    所属   研究施設 研究施設    職種   准教授
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Microautophagy in the yeast vacuole depends on the activities of phosphatidylinositol 4-kinases, Stt4p and Pik1p.
掲載誌名	正式名：Biochimica et biophysica acta. Biomembranes 略　 称：Biochim Biophys Acta Biomembr ISSNコード：18792642/00052736
掲載区分	国外
巻・号・頁	1862(11),pp.183416
著者・共著者	Kurokawa Yuna, Konishi Rikako, Yoshida Akane, Tomioku Kanna, Tanabe Kenji, Fujita Akikazu
発行年月	2020/11
概要	Morphologically, the lipophagy in yeast cell mimics microautophagy, which includes a direct amendment of the vacuolar membrane that engulfs lipid droplets (LDs). The molecular mechanism of the membrane modifications that elicits microautophagy still remains elusive. In this study, an analysis of membrane lipid distribution at a nanoscale level showed that PtdIns(4)P is localized in the cytoplasmic leaflet of microautophagic vesicles, which are derived when the vacuole's membrane domains engulfed LDs both in the stationary phase and in acute nitrogen starvation. Furthermore, the PtdIns(4)P-positive raft-like domains engulf LDs through a microautophagic mechanism. When single temperature-conditional mutants of STT4 or PIK1 PtdIns 4-kinases were used, in the vacuole of STT4 and PIK1 mutant cells, microautophagic vesicles drastically decreased at restrictive temperatures, and the labeling density of PtdIns(4)P on the microautophagic vesicles and the sizes of the mutants' microautophagic vesicles also decreased. These results suggest that both Stt4p and Pik1p have important roles in the microautophagy of the vacuole in the stationary phase and under nitrogen starvation conditions.
DOI	10.1016/j.bbamem.2020.183416
PMID	32726584