Journal Article

The cellular adaptor GULP1 interacts with ATG14 to potentiate autophagy and APP processing

Ngo, Jacky Chi Ki, Lau, Kwok-Fai, Yu, Zhicheng, Yuqi, Zhai, Chau, Dennis Dik-Long, Chan, Wai Wa Ray, Chan, Ho Yin Edwin, Chang, Raymond Chuen Chung

2024

Overview

Autophagy is a highly conserved catabolic mechanism by which unnecessary or dysfunctional cellular components are removed. The dysregulation of autophagy has been implicated in various neurodegenerative diseases, including Alzheimer’s disease (AD). Understanding the molecular mechanism(s)/molecules that influence autophagy may provide important insights into developing therapeutic strategies against AD and other neurodegenerative disorders. Engulfment adaptor phosphotyrosine-binding domain-containing protein 1 (GULP1) is an adaptor that interacts with amyloid precursor protein (APP) to promote amyloid-β peptide production via an unidentified mechanism. Emerging evidence suggests that GULP1 has a role in autophagy. Here, we show that GULP1 is involved in autophagy through an interaction with autophagy-related 14 (ATG14), which is a regulator of autophagosome formation. GULP1 potentiated the stimulatory effect of ATG14 on autophagy by modulating class III phosphatidylinositol 3-kinase complex 1 (PI3KC3-C1) activity. The effect of GULP1 is attenuated by a GULP1 mutation (GULP1m) that disrupts the GULP1–ATG14 interaction. Conversely, PI3KC3-C1 activity is enhanced in cells expressing APP but not in those expressing an APP mutant that does not bind GULP1, which suggests a role of GULP1–APP in regulating PI3KC3-C1 activity. Notably, GULP1 facilitates the targeting of ATG14 to the endoplasmic reticulum (ER). Moreover, the levels of both ATG14 and APP are elevated in the autophagic vacuoles (AVs) of cells expressing GULP1, but not in those expressing GULP1m. APP processing is markedly enhanced in cells co-expressing GULP1 and ATG14. Hence, GULP1 alters APP processing by promoting the entry of APP into AVs. In summary, we unveil a novel role of GULP1 in enhancing the targeting of ATG14 to the ER to stimulate autophagy and, consequently, APP processing.

• Publisher: Springer International Publishing,Springer Nature B.V
• Subject: 1-Phosphatidylinositol 3-kinase / Adapters / Adaptor Proteins, Signal Transducing - genetics / Adaptor Proteins, Signal Transducing - metabolism / Adaptor Proteins, Vesicular Transport - genetics / Adaptor Proteins, Vesicular Transport - metabolism / Alzheimer Disease - genetics / Alzheimer Disease - metabolism / Alzheimer Disease - pathology / Alzheimer's disease / amyloid / Amyloid beta-Protein Precursor - genetics / Amyloid beta-Protein Precursor - metabolism / Amyloid precursor protein / autophagosomes / Autophagy / Autophagy-Related Proteins - genetics / Autophagy-Related Proteins - metabolism / Biochemistry / Biomedical and Life Sciences / Biomedicine / Cell Biology / class / Class III Phosphatidylinositol 3-Kinases - genetics / Class III Phosphatidylinositol 3-Kinases - metabolism / Endoplasmic reticulum / HEK293 Cells / Humans / Kinases / Life Sciences / Molecular modelling / mutants / mutation / Neurodegenerative diseases / Original / Original Article / peptides / phosphatidylinositol 3-kinase / Phosphotyrosine / Protein Binding / Proteins / therapeutics / Vacuoles / Vesicular Transport Proteins - genetics / Vesicular Transport Proteins - metabolism / β-Amyloid