Location of the internal ribosome entry site in the 5' non-coding region of the immunoglobulin heavy-chain binding protein (BiP) mRNA: evidence for specific RNA-protein interactions.
The 220 nucleotide 5'non-coding region (5'NCR) of the human immunoglobulin heavy chain binding protein (BiP) mRNA contains an internal ribosome entry site (IRES) that mediates the translation of the second cistron in a dicistronic mRNA in cultured mammalian cells. In this study, experiments are presented that locate the IRES immediately upstream of the start-site AUG codon in the BiP mRNA. Furthermore, crosslinking of thiouridine-labeled BiP IRES-containing RNA to cellular proteins identified the specific binding of two proteins, p60 and p95, to the 3'half of the BiP 5'NCR. Interestingly, both p60 and p95 bound also specifically to several viral IRES elements. This correlation suggests that p60 and p95 could have roles in internal initiation of cellular and viral IRES elements.
Yang
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Department of Biochemistry, Biophysics and Genetics, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Denver, CO 80262, USA.
Sarnow
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P
D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D005796:Genes; D006367:HeLa Cells; D006360:Heat-Shock Proteins; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000378:metabolism*; D018832:Molecular Chaperones / Q000235:genetics* / Q000378:metabolism; D010442:Peptide Chain Initiation, Translational; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*
D002352:Carrier Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D007143:Immunoglobulin Heavy Chains; D018832:Molecular Chaperones; D012333:RNA, Messenger; D016601:RNA-Binding Proteins