Nucleotide sequence of human cDNA encoding eukaryotic initiation factor 4AI.

Eukaryotic initiation factor 4A (eIF-4A) is one of the factors required for the binding of mRNA to 40S ribosomal subunits (1). Nielsen et al. have reported a mouse eIF-4A cDNA encoding a protein of 390 arnino acid residues (2). Subsequently they have cloned two genes encoding eIF-4A variants (eIF-4AI and eIF-4AII) whose arnino acid sequences are 91% identical (3). The genes encoding the two proteins are differentially expressed in various tissues. The previous cDNA corresponds to eIF-4AI. The genomic DNA corresponding to eIF-4AI has also been cloned and sequenced by Reddy et al. (4). The eIF-4AI gene reconstituted from the exons encodes a protein of 406 amino acid residues which has a longer N-terminal sequence than one encoded by the cDNA. This discrepancy was explained by the artifact of the 5'-terminal sequence of the cDNA (3). We obtained a cDNA clone encoding a eIF-4AI-like protein