RNA recognition motif 2 of yeast Pab1p is required for its functional interaction with eukaryotic translation initiation factor 4G.
The eukaryotic mRNA 3' poly(A) tail and its associated poly(A)-binding protein (Pab1p) are important regulators of gene expression. One role for this complex in the yeast Saccharomyces cerevisiae is in translation initiation through an interaction with a 115-amino-acid region of the translation initiation factor eIF4G. The eIF4G-interacting domain of Pab1p was mapped to its second RNA recognition motif (RRM2) in an in vitro binding assay. Moreover, RRM2 of Pab1p was required for poly(A) tail-dependent translation in yeast extracts. An analysis of a site-directed Pab1p mutation which bound to eIF4G but did not stimulate translation of uncapped, polyadenylated mRNA suggested additional Pab1p-dependent events during translation initiation. These results support the model that the association of RRM2 of yeast Pab1p with eIF4G is a prerequisite for the poly(A) tail to stimulate the translation of mRNA in vitro.
Kessler
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Department of Molecular and Cell Biology, University of California at Berkeley, 94720, USA.
Sachs
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D039603:Eukaryotic Initiation Factor-4G; D015966:Gene Expression Regulation, Fungal; D010448:Peptide Initiation Factors / Q000235:genetics* / Q000378:metabolism; D039102:Poly(A)-Binding Proteins; D014176:Protein Biosynthesis; D012331:RNA, Fungal / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism
D039603:Eukaryotic Initiation Factor-4G; D010448:Peptide Initiation Factors; D039102:Poly(A)-Binding Proteins; D012331:RNA, Fungal; D016601:RNA-Binding Proteins