Phosphorylation of only serine-51 in protein synthesis initiation factor-2 is associated with inhibition of peptide-chain initiation in reticulocyte lysates.
We have examined the phosphorylation of the alpha-subunit of initiation factor-2 (eIF-2 alpha) in reticulocyte lysates in which translational shut-off was induced by haem-deficiency or by double-stranded RNA. To maximise the phosphorylation of eIF-2 alpha, lysates were supplemented with the broad spectrum phosphatase inhibitor microcystin. Under all conditions tested, serine-51 was the only residue to become labelled. This is consistent with the observation of only two species of eIF-2 alpha in isoelectric focusing/immunoblotting analyses of lysates treated as described above.
Price
N T
NT
Department of Biochemistry, School of Medical Sciences, University of Bristol, U.K.
Welsh
G I
GI
Proud
C G
CG
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002474:Cell-Free System; D015852:Eukaryotic Initiation Factor-2 / Q000302:isolation & purification / Q000378:metabolism*; D007525:Isoelectric Focusing; D010442:Peptide Chain Initiation, Translational; D010449:Peptide Mapping; D010748:Phosphopeptides / Q000302:isolation & purification; D010766:Phosphorylation; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism*; D012694:Serine
D015852:Eukaryotic Initiation Factor-2; D010748:Phosphopeptides; D012694:Serine; D000255:Adenosine Triphosphate