title: Proteomics analysis of starved cells revealed Annexin A1 as an important regulator of autophagic degradation.
abstract: Macroautophagy is involved in the bulk degradation of long-lived cytosolic proteins and subcellular organelles, which is important for the survival of cells during starvation. To identify potential players of the autophagy process, we subjected HCT116 cells cultured in complete medium and in Earle's balanced salt solution to proteomics analysis. In approximately 1500 protein spots detected, we characterized 52 unique proteins, whose expression levels were significantly changed following starvation. Notably, we found that Annexin A1 was significantly upregulated following starvation at both mRNA and protein levels. Inhibition of Annexin A1 expression with specific siRNA did not alter starvation-induced autophagy as measured by the level of lipidated LC3, but significantly reversed autophagy degradation as measured by the level of p62/SQSTM 1. Thus Annexin A1 seemed to be positively upregulated during starvation to promote autophagic degradation. Overall, the data presented in this study established a expression profile of the proteome in starved cells, which allowed the identification of proteins with potential significance in starvation-induced autophagy.
authors.affiliation: Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, PA 15261, United States.
authors.forename: Jeong-Han
authors.initials: JH
authors.lastname: Kang
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Yin
mesh_terms: D000596:Amino Acids / Q000172:deficiency*; D017305:Annexin A1 / Q000235:genetics / Q000378:metabolism*; D001343:Autophagy; D002460:Cell Line; D055785:Gene Knockdown Techniques; D006801:Humans; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D000596:Amino Acids; D017305:Annexin A1; D020543:Proteome; D034741:RNA, Small Interfering