Proteomics analysis of autophagy-deficient Atg7−/− MEFs reveals a close relationship between F-actin and autophagy

• DOI: 10.1016/j.bbrc.2013.06.111
• Publication Date: 2013-07-09T11:48:31Z
• Authors: Cuiqin Zhuo; Yuhua Ji; Zhenping Chen; Kaio Kitazato; Yangfei Xiang; Meigong Zhong; Qiaoli Wang; Ying Pei; Huaiqiang Ju; Yifei Wang
• Keywords: Proteomics; 0303 health sciences; Microscopy, Confocal; Fibroblasts; Embryo, Mammalian; Autophagy-Related Protein 7; Actins; Mice; 03 medical and health sciences; Phagosomes; Autophagy; Animals; Protein Interaction Maps; Microtubule-Associated Proteins; Cells, Cultured; Cell Line, Transformed

Autophagy plays a crucial role in a wide array of physiological processes. To uncover the complex regulatory networks and mechanisms underlying basal autophagy, we performed a quantitative proteomics analysis of autophagy-deficient mouse embryonic fibroblast cells (MEFs) using iTRAQ labeling coupled with on-line 2D LC/MS/MS. We quantified a total of 1234 proteins and identified 114 proteins that were significantly altered (90% confidence interval), including 48 up-regulated proteins and 66 down-regulated proteins. We determined that F-actin was disassembled in autophagy-deficient Atg7(-/-) MEFs. Treatment of the WT MEFs with cytochalasin D (CD), which induces F-actin depolymerization, significantly induced autophagosome formation. However, treatment with cytochalasin D also increased the protein level of p62 under starvation conditions, suggesting that depolymerization of F-actin impaired autophagosome maturation and that the intact F-actin network is required for basal and starvation-induced autophagy. Our results demonstrate a close relationship between F-actin and autophagy and provide the basis for further investigation of their interactions.