Association of the yeast poly(A) tail binding protein with translation initiation factor eIF-4G.
Although the cap structure and the poly(A) tail are on opposite ends of the mRNA molecule, previous work has suggested that they interact to enhance translation and inhibit mRNA degradation. Here we present biochemical data that show that the proteins bound to the mRNA cap (eIF-4F) and poly(A) tail (Pab1p) are physically associated in extracts from the yeast Saccharomyces cerevisiae. Specifically, we find that Pab1p co-purifies and co-immunoprecipitates with the eIF-4G subunit of eIF-4F. The Pab1p binding site on the recombinant yeast eIF-4G protein Tif4632p was mapped to a 114-amino-acid region just proximal to its eIF-4E binding site. Pab1p only bound to this region when complexed to poly(A). These data support the model that the Pablp-poly(A) tail complex on mRNA can interact with the cap structure via eIF-4G.
Tarun
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SZ
Department of Molecular and Cell Biology, University of California at Berkeley, 94720, USA.
Sachs
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D001665:Binding Sites; D039603:Eukaryotic Initiation Factor-4G; D010448:Peptide Initiation Factors / Q000302:isolation & purification / Q000378:metabolism*; D039102:Poly(A)-Binding Proteins; D011233:Precipitin Tests; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
D039603:Eukaryotic Initiation Factor-4G; D010448:Peptide Initiation Factors; D039102:Poly(A)-Binding Proteins; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins