title: Proteomics analysis of autophagy-deficient Atg7-/- MEFs reveals a close relationship between F-actin and autophagy.
abstract: 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.
authors.affiliation: College of Pharmacy, Jinan University, Guangzhou, China.
authors.forename: Cuiqin
authors.initials: C
authors.lastname: Zhuo
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Ji
authors.forename: Zhenping
authors.initials: Z
authors.lastname: Chen
authors.forename: Kaio
authors.initials: K
authors.lastname: Kitazato
authors.forename: Yangfei
authors.initials: Y
authors.lastname: Xiang
authors.forename: Meigong
authors.initials: M
authors.lastname: Zhong
authors.forename: Qiaoli
authors.initials: Q
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Pei
authors.forename: Huaiqiang
authors.initials: H
authors.lastname: Ju
authors.forename: Yifei
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000199:Actins / Q000235:genetics / Q000502:physiology*; D000818:Animals; D001343:Autophagy / Q000235:genetics*; D000071193:Autophagy-Related Protein 7; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000172:deficiency* / Q000235:genetics; D010588:Phagosomes / Q000378:metabolism / Q000473:pathology; D060066:Protein Interaction Maps / Q000235:genetics; D040901:Proteomics / Q000379:methods*
chemical_list: D000199:Actins; C502661:Atg7 protein, mouse; D008869:Microtubule-Associated Proteins; D000071193:Autophagy-Related Protein 7
keywords: Atg7; Autophagy-deficient MEFs; F-actin; Proteomics analysis