title: Two functional complexes formed by KH domain containing proteins with the 5' noncoding region of poliovirus RNA.
abstract: The 5' noncoding region of the poliovirus genome contains RNA structures important for replication and translation. Here we show that two closely related cellular poly(rC) binding proteins (PCBP1 and PCBP2) bind to the terminal cloverleaf structure and facilitate the interaction of the viral protein 3CD (the uncleaved precursor of the protease-polymerase). In addition, these cellular proteins bind to stem-loop IV of the internal ribosomal entry site. The proteins are cytoplasmic and largely associated with ribosomes; they appear to dimerize in solution and to form heterodimers when binding to stem-loop IV. Initiation of viral translation in Xenopus oocytes is strongly inhibited by co-injection of specific antibodies directed against PCBP1 or PCBP2, indicating that the poly(rC) binding proteins may facilitate this process. Furthermore, PCPB-depleted HeLa extracts translate poliovirus RNA inefficiently and the activity is partially restored by addition of recombinant PCBP proteins.
authors.affiliation: Department of Microbiology and Immunology, University of California, San Francisco 94143-0414, USA.
authors.forename: A V
authors.initials: AV
authors.lastname: Gamarnik
authors.forename: R
authors.initials: R
authors.lastname: Andino
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001483:Base Sequence; D001665:Binding Sites; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins; D005260:Female; D006367:HeLa Cells / Q000378:metabolism / Q000821:virology; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009865:Oocytes / Q000821:virology; D017955:Poliovirus / Q000235:genetics*; D014176:Protein Biosynthesis; D012367:RNA, Viral / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014157:Transcription Factors
chemical_list: D000906:Antibodies; D004268:DNA-Binding Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; C094604:PCBP1 protein, human; C501903:PCBP2 protein, human; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors