| Autor: |
Kaspar RL; Department of Biochemistry, University of Washington, Seattle 98195., Rychlik W, White MW, Rhoads RE, Morris DR |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of biological chemistry [J Biol Chem] 1990 Mar 05; Vol. 265 (7), pp. 3619-22. |
| Abstrakt: |
Ribosomal protein L32 mRNA moved from messenger ribonucleoprotein particles into polysomes following serum activation of quiescent Swiss 3T3 cells. This redistribution of the mRNA into a translationally active state began by 1 h and was complete by 3 h after activation. In contrast, actin mRNA showed no translational control, being found predominantly in polysomes in both quiescent and activated cultures. The phosphorylation state of eukaryotic initiation factor (eIF) 4E, which binds mRNA caps, was examined in parallel. eIF-4E phosphorylation was elevated by 1 h following serum activation and reached a peak by 3-5 h. Treatment of resting cells with phorbol ester also simultaneously stimulated eIF-4E phosphorylation and the movement of L32 mRNA into polysomes. These results are consistent with a model in which mitogen-induced phosphorylation increases the pool of active eIF-4E molecules, which in turn cause the recruitment of translationally controlled mRNAs to actively synthesizing ribosomes. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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