We have analysed the effect of transcription inhibitors on the polysomal localization of 5' terminal oligopyrimidine (TOP-) mRNAs. It is known that, in vertebrates, the translation of this group of mRNAs is regulated according to the growth status of the cell. Mitogenic stimulation of quiescent cells induces a rapid recruitment of TOP mRNAs from translationally inactive light messenger ribonucleoprotein particles to polysomes. It was found that administration of transcription inhibitors to resting cells causes a similar collective translational activation of TOP mRNAs, without affecting global translation. A number of transcription inhibitors were tested in amphibian and mammalian cultured cells. Actinomycin D (act D), cordycepin, and 5,6-dichloro-1-beta -d-ribofuranosylbenzimidazole caused a similar activation whereas alpha -amanitin or low doses of act D did not induce the translational response. Concentrations of act D sufficient to induce TOP mRNA translation also induce 40S ribosomal protein S6 kinases 1 (S6K1) activation. Moreover at these concentrations of act D increased phosphorylation of 4E-BP1 was also observed, indicating the involvement of FRAP/mTOR. Consistent with this observation, pretreatment of resting cells with rapamycin suppresses the activation of TOP mRNA translation induced by act D. These results indicate that the effect of act D on translation is mediated by the S6Ks through FRAP/mTOR.
Loreni, F., Thomas, G., & Amaldi, F. (2000). Transcription inhibitors stimulate translation of 5 ' TOP mRNAs through activation of S6 kinase and the mTOR/FRAP signalling pathway. EUROPEAN JOURNAL OF BIOCHEMISTRY, 267(22), 6594-6601.
|Tipologia:||Articolo su rivista|
|Citazione:||Loreni, F., Thomas, G., & Amaldi, F. (2000). Transcription inhibitors stimulate translation of 5 ' TOP mRNAs through activation of S6 kinase and the mTOR/FRAP signalling pathway. EUROPEAN JOURNAL OF BIOCHEMISTRY, 267(22), 6594-6601.|
|IF:||Con Impact Factor ISI|
|Settore Scientifico Disciplinare:||Settore BIO/11|
|Revisione (peer review):||Sì, ma tipo non specificato|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1046/j.1432-1327.2000.01753.x|
|Stato di pubblicazione:||Pubblicato|
|Data di pubblicazione:||2000|
|Titolo:||Transcription inhibitors stimulate translation of 5 ' TOP mRNAs through activation of S6 kinase and the mTOR/FRAP signalling pathway|
|Autori:||Loreni, F; Thomas, G; Amaldi, F|
|Appare nelle tipologie:||01 - Articolo su rivista|