Baricevic, Marianne Michelle. Expression and analysis of ricin A chain in Saccharomyces cerevisiae. Retrieved from https://doi.org/doi:10.7282/T390245J
DescriptionRicin is a ribosome inactivating protein (RIP) isolated from ricinus communis, the castor bean plant. RIPs catalytically depurinate an adenine residue from the highly conserved sarcin/ricin loop in the large ribosomal RNA subunit, rendering the ribosome unable to translate protein. Due to its potential use as a bioweapon, understanding how ricin gains access to and depurinates ribosomes is of high importance. There is currently no approved vaccine or treatment for ricin intoxication. Learning the residues that are critical for ricin toxicity and enzymatic activity may help to generate a potential vaccine for ricin exposure. Here, I describe an analysis of ricin A chain (RTA), the enzymatic subunit of ricin, in Saccharomyces cerevisiae. The results provide evidence that ricin cytotoxicity is not necessarily a result of ribosome depurination and translation inhibition, ricin utilizes components of the ER Association Degradation (ERAD) pathway to reach the cytosol from the ER and the C-terminus of RTA is essential for enzymatic activity and protein translocation across the ER membrane.