title: Chicken Y-box proteins chk-YB-1b and chk-YB-2 repress translation by sequence-specific interaction with single-stranded RNA.
abstract: Y-Box proteins comprise a large family of multifunctional proteins with a wide spectrum of activities in both transcription and translational regulation of gene expression. Earlier, we have reported on the involvement of chk-YB-2 in transcriptional regulation of Rous sarcoma virus long terminal repeats and the involvement of chk-YB-1b in transcriptional regulation of alpha1(I) collagen genes. Here, we have investigated the potential role of chk-YB-2 and chk-YB-1b in RNA metabolism. We report that chk-YB-2 and chk-YB-1b are localized predominantly in the cytoplasm and that they both can bind single-stranded RNA in a sequence-specific and reversible manner. Well-conserved cold-shock domain, N-terminal proline-rich domain and the alternating clusters of acidic and basic amino acids located in the C-terminal ends of these two proteins were all found to be necessary for their RNA-binding ability. Further, we demonstrate that these two proteins inhibit translation in vitro and that binding to RNA is required for this inhibition. The significance of these results is discussed.
authors.affiliation: Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri-Columbia, Columbia, MO 65212, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Swamynathan
authors.forename: A
authors.initials: A
authors.lastname: Nambiar
authors.forename: R V
authors.initials: RV
authors.lastname: Guntaka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens; D003094:Collagen / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D014176:Protein Biosynthesis; D012313:RNA / Q000737:chemistry / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017384:Sequence Deletion; D014157:Transcription Factors; D014162:Transfection; D051840:Y-Box-Binding Protein 1
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D008164:Luminescent Proteins; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D049452:Green Fluorescent Proteins; D012313:RNA; D003094:Collagen