Autophagy is a major degradation system which processes substrates through the steps of auto- phagosome formation, autophagosome-lysosome fusion, and substrate degradation. Aberrant autophagic flux is present in many ...Autophagy is a major degradation system which processes substrates through the steps of auto- phagosome formation, autophagosome-lysosome fusion, and substrate degradation. Aberrant autophagic flux is present in many pathological conditions including neurodegeneration and tumors. CHIP/STUB1, an E3 ligase, plays an important role in neurodegeneration. In this study, we identified the regulation of autophagic flux by CHIP （carboxy-terminus of HscT0-interacting protein）. Knockdown of CHIP induced autophagosome formation through increasing the PTEN protein level and decreasing the AKT/mTOR activity as well as decreasing phosphorylation of ULK1 on Ser757. However, degradation of the autophagic substrate p62 was disturbed by knockdown of CHIP, suggesting an abnormality of autophagic flux. Furthermore, knockdown of CHIP increased the susceptibility of cells to autophagic cell death induced by bafilomycin AI. Thus, our data suggest that CHIP plays roles in the regulation of autophagic flux.展开更多
基金supported in part by the National Natural Science Foundation of China (31330030 and 31471012)the National Basic Research Development Program of China (2012CB947602)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Autophagy is a major degradation system which processes substrates through the steps of auto- phagosome formation, autophagosome-lysosome fusion, and substrate degradation. Aberrant autophagic flux is present in many pathological conditions including neurodegeneration and tumors. CHIP/STUB1, an E3 ligase, plays an important role in neurodegeneration. In this study, we identified the regulation of autophagic flux by CHIP （carboxy-terminus of HscT0-interacting protein）. Knockdown of CHIP induced autophagosome formation through increasing the PTEN protein level and decreasing the AKT/mTOR activity as well as decreasing phosphorylation of ULK1 on Ser757. However, degradation of the autophagic substrate p62 was disturbed by knockdown of CHIP, suggesting an abnormality of autophagic flux. Furthermore, knockdown of CHIP increased the susceptibility of cells to autophagic cell death induced by bafilomycin AI. Thus, our data suggest that CHIP plays roles in the regulation of autophagic flux.
