title: Proteomic Analysis of the EWS-Fli-1 Interactome Reveals the Role of the Lysosome in EWS-Fli-1 Turnover.
abstract: Ewing sarcoma is a cancer of bone and soft tissue in children that is characterized by a chromosomal translocation involving EWS and an Ets family transcription factor, most commonly Fli-1. EWS-Fli-1 fusion accounts for 85% of cases. The growth and survival of Ewing sarcoma cells are critically dependent on EWS-Fli-1. A large body of evidence has established that EWS-Fli-1 functions as a DNA-binding transcription factor that regulates the expression of a number of genes important for cell proliferation and transformation. However, little is known about the biochemical properties of the EWS-Fli-1 protein. We undertook a series of proteomic analyses to dissect the EWS-Fli-1 interactome. Employing a proximity-dependent biotinylation technique, BioID, we identified cation-independent mannose 6-phosphate receptor (CIMPR) as a protein located in the vicinity of EWS-Fli-1 within a cell. CIMPR is a cargo that mediates the delivery of lysosomal hydrolases from the trans-Golgi network to the endosome, which are subsequently transferred to the lysosomes. Further molecular cell biological analyses uncovered a role for lysosomes in the turnover of the EWS-Fli-1 protein. We demonstrate that an mTORC1 active-site inhibitor, torin 1, which stimulates the TFEB-lysosome pathway, can induce the degradation of EWS-Fli-1, suggesting a potential therapeutic approach to target EWS-Fli-1 for degradation.
authors.affiliation: †Greehey Children's Cancer Research Institute and ‡Department of Biochemistry, The University of Texas Health Science Center, San Antonio, Texas 78229-3900, United States.
authors.forename: David J
authors.initials: DJ
authors.lastname: Elzi
authors.affiliation: †Greehey Children's Cancer Research Institute and ‡Department of Biochemistry, The University of Texas Health Science Center, San Antonio, Texas 78229-3900, United States.
authors.forename: Meihua
authors.initials: M
authors.lastname: Song
authors.affiliation: †Greehey Children's Cancer Research Institute and ‡Department of Biochemistry, The University of Texas Health Science Center, San Antonio, Texas 78229-3900, United States.
authors.forename: Kevin
authors.initials: K
authors.lastname: Hakala
authors.affiliation: †Greehey Children's Cancer Research Institute and ‡Department of Biochemistry, The University of Texas Health Science Center, San Antonio, Texas 78229-3900, United States.
authors.forename: Susan T
authors.initials: ST
authors.lastname: Weintraub
authors.affiliation: †Greehey Children's Cancer Research Institute and ‡Department of Biochemistry, The University of Texas Health Science Center, San Antonio, Texas 78229-3900, United States.
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Shiio
mesh_terms: D019921:Biotinylation; D020134:Catalytic Domain; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008247:Lysosomes / Q000378:metabolism*; D000076222:Mechanistic Target of Rapamycin Complex 1; D046912:Multiprotein Complexes / Q000378:metabolism; D015514:Oncogene Proteins, Fusion / Q000502:physiology*; D020543:Proteome / Q000378:metabolism; D040901:Proteomics; D051789:Proto-Oncogene Protein c-fli-1 / Q000502:physiology*; D034802:RNA-Binding Protein EWS / Q000502:physiology*; D012512:Sarcoma, Ewing / Q000188:drug therapy* / Q000473:pathology; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D014157:Transcription Factors / Q000378:metabolism; D021601:trans-Golgi Network / Q000378:metabolism
chemical_list: C106031:EWS-FLI fusion protein; D046912:Multiprotein Complexes; D015514:Oncogene Proteins, Fusion; D020543:Proteome; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases
keywords: EWS-Fli-1; Ewing sarcoma; interactome; lysosome; protein degradation; proximity-dependent biotinylation