cAMP-dependent activation of protein synthesis correlates with dephosphorylation of elongation factor 2

• Published in: FEBS letters Vol. 228; no. 2; pp. 327 - 331
• Main Authors: Sitikov, A.S., Simonenko, P.N., Shestakova, E.A., Ryazanov, A.G., Ovchinnikov, L.P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-02-1988; Elsevier
• Subjects: Adenosine Triphosphate - metabolism; Animals; Biological and medical sciences; Cell-Free System; Cyclic AMP - pharmacology; cyclic AMP-dependent activation; Elongation factor 2; Fundamental and applied biological sciences. Psychology; Isoelectric Point; Kinetics; Molecular and cellular biology; Molecular genetics; Peptide Biosynthesis; Peptide Elongation Factor 2; Peptide Elongation Factors - metabolism; Peptides; Phosphorylation; Poly U - metabolism; Protein Biosynthesis - drug effects; Protein phosphorylation; Protein synthesis regulation; Rabbit reticulocyte; Rabbits; Reticulocytes - metabolism; Translation. Translation factors. Protein processing; Protein synthesis regulation; Rabbit reticulocyte; Protein phosphorylation; cyclic AMP-dependent activation; Elongation factor 2; Vertebrata; Regulation(control); Mammalia; In vitro translation; AMP; Elongation factor EF2; Rabbit; Reticulocyte; Dephosphorylation; Lagomorpha
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(88)80025-5

The addition of 5 mM cAMP to a cell-free translation system from rabbit reticulocytes increases the rate of protein synthesis 3–5-fold. Lower concentrations of cAMP (0.005, 0.05 and 0.5 mM) have no effect on translation in this system. cAMP at all the concentrations tested stimulates the phosphorylation of the same pattern of polypeptides, while 5 mM cAMP additionally stimulates dephosphorylation of the 95 kDa polypeptide identified as elongation factor 2 (EF-2). Testing of the preparations of EF-2 with a different content of the phosphorylated form in poly(U)-directed poly(Phe) synthesis reveals that the EF-2 activity correlates with the fraction of non-phosphorylated EF-2. Thus cAMP-dependent activation of protein synthesis seems to be due to dephosphorylation of EF-2.