Stage Master

An internship is available in the group « dynamics and disorders of ribosome synthesis », (group leader : Pr. Pierre-Emmanuel Gleizes), to determine 3D structures of precursors to the small ribosomal subunit (pre-40S particles) by cryo-EM and image analysis.
Ribosome assembly is a very complex process, that must be finely regulated to quickly adapt to cellular needs. It requires the production and the correct assembly of ~80 ribosomal proteins (RPs) with 4 ribosomal RNAs (rRNAs), and the transient intervention of more than 200 ribosomal assembly factors (RAFs) (Kressler et al., 2017). Defects in ribosome synthesis have been recently associated to an increasing list of human genetic diseases (called ribosomopathies) and cancers, which calls for a precise understanding of each and every step of ribosome biogenesis. Molecular and functional studies have allowed to define several successive cytoplasmic maturation steps of eukaryotic pre-40S particles. However, little is known about the 3D structures of these precursors. Using cryo-EM and single particle analysis, our lab has solved the first 3D structure of a human pre-40S particle (Larburu et al., 2016), and is currently working on other maturation intermediates, both in yeast and human cells.
The candidate will purify pre-40S particles from human and/or yeast cells, then use cryo-EM followed by image analysis softwares to determine their 3D structure. He/she will then compare them with other existing pre-40S subunits structures, in order to shed light on the structural remodeling events occuring throughout small ribosomal subunits maturation process.This work will be performed in a multidisciplinary group, which combines structural analysis of pre-ribosomal particles with functional studies of the molecular mechanisms underlying ribosome synthesis (http://cbi-toulouse.fr/fr/equipe-pierre-emmanuel-gleizes).