Isolation and characterization of Atg9-containing membrane structures

2015 Fiscal Year Final Research Report

• Project/Area Number: 25860149
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: General anatomy (including histology/embryology)
• Research Institution: Juntendo University
• Principal Investigator: KAKUTA Soichiro 順天堂大学, 医学(系)研究科(研究院), 助教 (80551209)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: オートファジー / 小胞輸送 / 電子顕微鏡 / 形態解析 / 質量分析

Outline of Final Research Achievements

Atg9 is a membrane protein essential for autophagy and considered to be directly involved in the autophagosome formation. Mammalian Atg9A was reported to be localized to trans-Golgi network and endosomal compartment. For dissecting the Atg9A-containing membranes, we examined subcellular localization of Atg9A and performed immunoisolation of those membranes. Atg9A-GFP in human culture cells was observed as numerous puncta that move rapidly throughout the cytoplasm. We succeeded in isolation of these cytoplasmic membranes, and revealed that they were small vesicles by electron microscopy. Proteomic analyses revealed that isolated these vesicles contained proteins including Rab1, a small GTPase in ER-Golgi vesicle trafficking. In Rab1B-depleted cells, Atg9A accumulated on intermediate membrane structures at autophagosome formation site. These results indicated that Rab1B is involved in the regulation of proper development of autophagosome.

Free Research Field

オートファジー