Cloning and expression of eukaryotic initiation factor 4B cDNA: sequence determination identifies a common RNA recognition motif

• Published in: The EMBO journal 1990-09, Vol.9 (9), p.2783-2790
• Main Authors: Milburn, S. C., Hershey, J. W., Davies, M. V., Kelleher, K., Kaufman, R. J.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Binding Sites; Biological and medical sciences; Cell Line; Cloning, Molecular; Eukaryotic Initiation Factors; Fundamental and applied biological sciences. Psychology; Gene Expression; genes; Genes. Genome; HeLa cells; HeLa Cells - metabolism; Humans; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Oligonucleotide Probes; Peptide Fragments - isolation & purification; Peptide Initiation Factors - genetics; Protein Conformation; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sequence Homology, Nucleic Acid; Transfection
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1002/j.1460-2075.1990.tb07466.x

Eukaryotic protein synthesis initiation factor 4B (eIF‐4B) is an 80,000 dalton polypeptide which is essential for the binding of mRNA to ribosomes. A highly purified preparation of eIF‐4B from HeLa cells was subjected to enzymatic cleavage and amino‐terminal amino acid sequence analysis. Degenerate oligonucleotide probes were used to isolate a 3851 bp cDNA encoding eIF‐4B from a human cDNA library. The DNA encodes a protein comprising 611 residues with a mass of 69,843 daltons. The amino‐terminal domain of eIF‐4B contains a consensus RNA binding domain present in a number of other RNA binding proteins. Expression of eIF‐4B in transfected COS‐1 cells yielded a polypeptide which reacted with anti‐eIF‐4B antiserum and comigrated with purified eIF‐4B. Expression of eIF‐4B in COS‐1 cells resulted in a general inhibition of translation, possibly due to a 50‐fold eIF‐4B overproduction.