title: RNA-binding specificity of Y-box protein 1.
abstract: Y-box protein 1 (YB-1) is a multifunctional DNA/RNA-binding protein that regulates transcription and translation. The specificity of YB-1's RNA binding and its consequences are unknown. Because expression and subcellular localization of YB-1 have been reported to be important in breast cancer, we determined the specificity and functional impact of YB-1 mRNA-binding in MCF7 breast cancer cells. We used YB-1 antibodies to immunoprecipitate YB-1 and microarray profiling to compare YB-1-bound and total poly(A) RNA. We demonstrated that YB-1 mRNA-binding was preferential. Transcript sequences significantly associated with this binding had high GC content. Selected YB-1 mRNA-binding targets were confirmed by QRT-PCR. However, downregulation of YB-1 levels by siRNA did not affect their RNA or protein expression. Thus, YB-1 has RNA-binding specificity; however, YB-1 binding does not necessarily regulate the stability or translation of its mRNA targets. Further study is needed to determine the functional consequences of selective YB-1 mRNA binding.
authors.affiliation: Department of Surgical Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Jinjiang
authors.initials: J
authors.lastname: Dong
authors.forename: Argun
authors.initials: A
authors.lastname: Akcakanat
authors.forename: David N
authors.initials: DN
authors.lastname: Stivers
authors.forename: Jiexin
authors.initials: J
authors.lastname: Zhang
authors.forename: Doyil
authors.initials: D
authors.lastname: Kim
authors.forename: Funda
authors.initials: F
authors.lastname: Meric-Bernstam
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism; D045744:Cell Line, Tumor; D004247:DNA / Q000737:chemistry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008954:Models, Biological; D009687:Nuclear Proteins / Q000737:chemistry; D009711:Nucleotides / Q000737:chemistry; D020411:Oligonucleotide Array Sequence Analysis; D011485:Protein Binding; D012313:RNA / Q000737:chemistry*; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D019076:Transgenes; D051840:Y-Box-Binding Protein 1 / Q000378:metabolism*
chemical_list: D009687:Nuclear Proteins; D009711:Nucleotides; D012333:RNA, Messenger; D051840:Y-Box-Binding Protein 1; D012313:RNA; D004247:DNA