- Accueil >
- Publications >
- Cytoplasmic Relocalization of Heterogeneous Nuclear Ribonucleoprotein A1 Controls Translation Initiation of Specific mRNAs
Cytoplasmic Relocalization of Heterogeneous Nuclear Ribonucleoprotein A1 Controls Translation Initiation of Specific mRNAs
Auteurs
Anne Cammas, Frédéric Pileur, Sophie Bonnal, Stephen M. Lewis, Nicolas Lévêque, Martin Holcik, Stéphan Vagner
Résumé
Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is a nucleocytoplasmic shuttling protein that regulates gene expression through its action on mRNA metabolism and translation. The cytoplasmic redistribution of hnRNP A1 is a regulated process during viral infection and cellular stress. Here, we show that hnRNP A1 is an internal ribosome entry site (IRES) trans-acting factor that binds specifically to the 5′ untranslated region of both the human rhinovirus-2 and the human apoptotic peptidase activating factor 1 (apaf-1) mRNAs, thereby regulating their translation. Furthermore, the cytoplasmic redistribution of hnRNP A1 after rhinovirus infection leads to enhanced rhinovirus IRES-mediated translation, whereas the cytoplasmic relocalization of hnRNP A1 after UVC irradiation limits the UVC-triggered translational activation of the apaf-1 IRES. Therefore, this study provides a direct demonstration that IRESs behave as translational enhancer elements regulated by specific trans-acting mRNA binding proteins in given physiological conditions. Our data highlight a new way to regulate protein synthesis in eukaryotes through the subcellular relocalization of a nuclear mRNA-binding protein.
Membres
