title: An acidic protein, YBAP1, mediates the release of YB-1 from mRNA and relieves the translational repression activity of YB-1.
abstract: Eukaryotic Y-box proteins are nucleic acid-binding proteins implicated in a wide range of gene regulatory mechanisms. They contain the cold shock domain, which is a nucleic acid-binding structure also found in bacterial cold shock proteins. The Y-box protein YB-1 is known to be a core component of messenger ribonucleoprotein particles (mRNPs) in the cytoplasm. Here we disrupted the YB-1 gene in chicken DT40 cells. Through the immunoprecipitation of an epitope-tagged YB-1 protein, which complemented the slow-growth phenotype of YB-1-depleted cells, we isolated YB-1-associated complexes that likely represented general mRNPs in somatic cells. RNase treatment prior to immunoprecipitation led to the identification of a Y-box protein-associated acidic protein (YBAP1). The specific association of YB-1 with YBAP1 resulted in the release of YB-1 from reconstituted YB-1-mRNA complexes, thereby reducing the translational repression caused by YB-1 in the in vitro system. Our data suggest that YBAP1 induces the remodeling of YB-1-mRNA complexes.
authors.affiliation: Laboratory of Cellular Biochemistry, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. matsumok@postman.riken.go.jp
authors.forename: Ken
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Kimio J
authors.initials: KJ
authors.lastname: Tanaka
authors.forename: Masafumi
authors.initials: M
authors.lastname: Tsujimoto
mesh_terms: D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D049109:Cell Proliferation; D002645:Chickens / Q000235:genetics; D003080:Cold Temperature; D015536:Down-Regulation / Q000235:genetics / Q000502:physiology; D005816:Genetic Complementation Test; D047468:Immunoprecipitation; D016254:Mutagenesis, Insertional / Q000235:genetics; D051839:NFI Transcription Factors; D014176:Protein Biosynthesis / Q000235:genetics* / Q000502:physiology; D025941:Protein Interaction Mapping; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051840:Y-Box-Binding Protein 1
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D051839:NFI Transcription Factors; D012333:RNA, Messenger; D012097:Repressor Proteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C026452:messenger ribonucleoprotein