Cloning and sequencing of complementary DNAs encoding the alpha-subunit of translational initiation factor eIF-2. Characterization of the protein and its messenger RNA.

摘要: A clone encoding the alpha-subunit of eukaryotic initiation factor 2 (eIF-2 alpha) was isolated from a lambda gt11 expression library rat brain cDNAs. The fusion protein expressed by recombinant phage reacts with eIF-2 alpha antiserum except when serum is preadsorbed pure eIF-2. translation hybrid-selected HeLa cell mRNA produces two proteins which are indistinguishable authentic and its phosphorylated form analyzed electrophoresis in two-dimensional isoelectrofocusing/sodium dodecyl sulfate-polyacrylamide gels partial protease digestion. migrates as single band about 1600 nucleotides. cDNA insert sequenced, region coding for identified. human obtained hybridization screening cDNA, sequence determined also. Both comprise 315 amino acids (36.1 kDa) differ only three acids. found exclusively polysomes containing 10 or more ribosomes exponentially growing cells. In serum-depleted cells synthesize bulk slowly than exponential cells, level not changed, average polysome size reduced to 7, little no detected ribonucleoprotein fraction. These results consistent view that very efficient compared other mRNAs cell.