Investigating the consequences of human disease related mutations on 60S ribosome assembly and function in yeast

In actively growing yeast cells, thousands of ribosomes are synthesized per minute. After rapid assembly, these complex machines must faithfully translate mRNA into the cell’s proteome, making it crucial that immature and functionally defective ribosomal subunits do not enter the translating pool. The eukaryotic ribosome biogenesis pathway is a complex series of assembly events that involves the transcription and processing of ribosomal RNA along with its folding and assembly with approximately 80 ribosomal proteins. This pathway includes quality control checkpoints, including a translation-like “test-drive” of the large (60S) subunit during final cytoplasmic maturation. In this work, I use the budding yeast Saccharomyces cerevisiae as a model to study the consequences of mutations in genes associated with 60S quality control. I show that a mutation associated with T-cell acute lymphoblastic leukemia, rpl10-R98S, blocks the final two steps of large subunit ribosome maturation in yeast. Through my analysis of rpl10-R89S, I provide important new insights into mechanisms involved in 60S maturation in the cytoplasm, and demonstrate that the major 60S quality control checkpoint can be bypassed through multiple pathways.Microbiolog