Analyses of WIPI family as a PI(3,5)P2 effector

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K18505
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Functional biochemistry
• Research Institution: Fukushima Medical University
• Principal Investigator: Tamura Naoki 福島県立医科大学, 医学部, 助教 (70745992)
• Research Collaborator: Zhang Hong
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: オートファジー / 高浸透圧ストレス / WIPI / Ulk複合体

Outline of Final Research Achievements

In this study, I focused on functions of WIPI family as a PI(3,5)P2-binding effector. First, I analyzed the subcellular localization of WIPI family under various conditions that the amount of PI(3,5)P2 was changed. As a result, WIPI-1 and WIPI-2 displayed punctate structures when cells were exposed to hyperosmotic stresses. Under hyperosmotic stresses, WIPI-1 and WIPI-2 were co-localized with autophagosomes and p62, a substrate of selective autophagy, was transported to lysosomes for degradation. Taken together, I concluded that an autophagic pathway is induced in response to hyperosmotic stresses. Unexpectedly, WIPI-1 and WIPI-2 functioned as a PI(3)P, a precursor of PI(3,5)P2, effector, but not as a PI(3,5)P2 effector. Interestingly, this autophagy did not require the Ulk complex in contrast to starvation-induced autophagy.

Free Research Field

細胞生物学