JBC, Vol. 253, Issue 23, 8578-8582, Dec, 1978
Stimulation of the protein synthetic process by adenosine 3':5'-monophosphate and hexose phosphates in gel-filtered rabbit reticulocyte lysates
J. M. Wu, C. P. Cheung and R. J. Suhadolnik
The addition of 0.167 to 4.0 mM cAMP to gel-filtered rabbit reticulocyte
lysates stimulates the initial rate and the extent of polypeptide
synthesis. The stimulation is at the initiation step of polypeptide
synthesis as measured by the (i) increased dipeptide, methionyl-valine,
accumulation in the presence of the specific initiation inhibitor,
pactamycin, and (ii) increased formation of the 40 S and 80 S initiation
complex when gel-filtered lysates are incubated with [35S]Met-tRNAFMet.
Furthermore, a synergistic stimulation of protein synthesis is observed
when cAMP and hexose phosphates (which alone elicit a 1.8-fold stimulation
of protein synthesis) are added simultaneously to gel-filtered rabbit
reticulocyte lysates. These results indicate that cAMP and hexose
phosphates are both essential to maintain the high rate of initiation.