Deletion of EFL1 Results in Heterogeneity of the 60S GTPase-associated rRNA Conformation - Université Pierre et Marie Curie Accéder directement au contenu
Article Dans Une Revue Journal of Molecular Biology Année : 2005

Deletion of EFL1 Results in Heterogeneity of the 60S GTPase-associated rRNA Conformation

Résumé

Previous work suggested that the release of the nucleolar Tif6 from nascent 60 S subunits occurs in the cytoplasm and requires the cytoplasmic EF-2-like GTPase, Efl1. To check whether this release involves an rRNA structural rearrangement mediated by Efl1, we analyzed the rRNA conformation of the GTPase center of 80 S ribosomes in three contexts: wild-type, Deltaefl1 and a dominant suppressor R1 of Deltaefl1. This analysis was restricted to domain II and VI of 25 S rRNA. The rRNA analysis of R1 ribosomes allows us to distinguish the effects due to depletion of Efl1 from the resulting nucleolar deficit of Tif6. Efl1 inhibits the EF-2 GTPase activity, suggesting that the two proteins share a similar ribosome-binding site. The 80 S ribosomes from either type failed to show any difference of conformation in the two rRNA domains analyzed. However, the same analysis performed on the pool of free 60 S subunits reveals several rRNA conformational differences between wild-type and Deltaefl1 subunits, whereas that from the suppressor strain is similar to wild-type. This suggests that the nucleolar deficit of Tif6 during assembly of the 60 S preribosomes is responsible for the changes in rRNA conformation observed in Deltaefl1 60 S subunits. We also purified 60 S preribosomes from the three genetic contexts by TAP-tagging Tif6. The protein content of 60 S preribosomes associated with Tif6p in a Deltaefl1 strain are obtained at a lower yield but have, surprisingly, a protein composition that is a priori similar to that of wild-type and the suppressor strain.

Dates et versions

hal-02370162 , version 1 (19-11-2019)

Identifiants

Citer

Jean-Sébastien Graindorge, Jean-Claude Rousselle, Bruno Senger, Pascal Lenormand, Abdelkader Namane, et al.. Deletion of EFL1 Results in Heterogeneity of the 60S GTPase-associated rRNA Conformation. Journal of Molecular Biology, 2005, 352 (2), pp.355-369. ⟨10.1016/j.jmb.2005.07.037⟩. ⟨hal-02370162⟩
34 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More