The N-terminal K homology domain of the poly(rC)-binding protein is a major determinant for binding to the poliovirus 5'-untranslated region and acts as an inhibitor of viral translation.
The poly(rC)-binding proteins (PCBP1 and PCBP2) are RNA-binding proteins whose RNA recognition motifs are composed of three K homology (KH) domains. These proteins are involved in both the stabilization and translational regulation of several cellular and viral RNAs. PCBP1 and PCBP2 specifically interact with both the 5'-element known as the cloverleaf structure and the large stem-loop IV RNA of the poliovirus 5'-untranslated region. We have found that the first KH domain of PCBP2 (KH1) specifically interacts with the viral RNAs, and together with viral protein 3CD, KH1 forms a high affinity ternary ribonucleoprotein complex with the cloverleaf RNA, resembling the full-length PCBP protein. Furthermore, KH1 acts as a dominant-negative mutant to inhibit translation from a poliovirus reporter gene in both Xenopus laevis oocytes and HeLa cell in vitro translation extracts.
Silvera
D
D
Department of Microbiology, University of California, San Francisco, California 94143-0414, USA.
Gamarnik
A V
AV
Andino
R
R
D020121:5' Untranslated Regions; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D001665:Binding Sites; D017931:DNA Primers; D004268:DNA-Binding Proteins; D006367:HeLa Cells; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D017955:Poliovirus / Q000235:genetics*; D014176:Protein Biosynthesis / Q000502:physiology*; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D012270:Ribosomes / Q000378:metabolism; D014157:Transcription Factors
D020121:5' Untranslated Regions; D017931:DNA Primers; D004268:DNA-Binding Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; C094604:PCBP1 protein, human; C501903:PCBP2 protein, human; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D014157:Transcription Factors