A newly identified N-terminal amino acid sequence of human eIF4G binds poly(A)-binding protein and functions in poly(A)-dependent translation
| Autor: | Alessandra Gradi, Hiroaki Imataka, Nahum Sonenberg |
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| Rok vydání: | 1998 |
| Předmět: |
Molecular Sequence Data
Biology Poly(A)-Binding Proteins General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound Eukaryotic translation Peptide Initiation Factors Poly(A)-binding protein Protein biosynthesis Humans Amino Acid Sequence RNA Messenger Molecular Biology Peptide sequence Binding Sites General Immunology and Microbiology Sequence Homology Amino Acid EIF4G General Neuroscience RNA-Binding Proteins Translation (biology) Precipitin Tests Peptide Fragments Recombinant Proteins Open reading frame chemistry Biochemistry Protein Biosynthesis biology.protein Eukaryotic Initiation Factor-4G Poly(A)-Binding Protein I Protein Binding Research Article |
| Zdroj: | The EMBO journal. 17(24) |
| ISSN: | 0261-4189 |
| Popis: | Most eukaryotic mRNAs possess a 5' cap and a 3' poly(A) tail, both of which are required for efficient translation. In yeast and plants, binding of eIF4G to poly(A)-binding protein (PABP) was implicated in poly(A)-dependent translation. In mammals, however, there has been no evidence that eIF4G binds PABP. Using 5' rapid amplification of cDNA, we have extended the known human eIF4GI open reading frame from the N-terminus by 156 amino acids. Co-immunoprecipitation experiments showed that the extended eIF4GI binds PABP, while the N-terminally truncated original eIF4GI cannot. Deletion analysis identified a 29 amino acid sequence in the new N-terminal region as the PABP-binding site. The 29 amino acid stretch is almost identical in eIF4GI and eIF4GII, and the full-length eIF4GII also binds PABP. As previously shown for yeast, human eIF4G binds to a fragment composed of RRM1 and RRM2 of PABP. In an in vitro translation system, an N-terminal fragment which includes the PABP-binding site inhibits poly(A)-dependent translation, but has no effect on translation of a deadenylated mRNA. These results indicate that, in addition to a recently identified mammalian PABP-binding protein, PAIP-1, eIF4G binds PABP and probably functions in poly(A)-dependent translation in mammalian cells. |
| Databáze: | OpenAIRE |
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