Seminar

Establishing Systems to Investigate Rack1 Signaling Complexes on the 80S Ribosome

Sean Connell, PhD

Pathological conditions like disease, cancer and bacterial/viral infection are able to modulate cellular networks that regulate protein synthesis, which, in eukaryotes, is carried out by the 80S ribosome, a large complex of RNA and proteins. This regulation of translation (activity, specificity and/or sub-cellular localization) results from the recruitment of signaling proteins to the ribosome. The protein RACK1 plays a key role in mediating these interactions by acting as a scaffolding protein to facilitate the assembly of signaling molecules into dynamic RACK1-dependent signaling complexes (RSC). We will use a variant of the split-ubiquitin yeast two-hybrid screen (SUS) to search for cellular and pathogen proteins that comprise these RSC and subsequently cryo-EM will be employed to characterize the ribosome bound by these proteins generating a '3D library' describing the RACK1 interaction network. I will present (1) on-going work in establishing the variant of the SUS and (2) results from cryo-EM investigations of ribosomal complexes that provide the framework for studying the RSC.