Eukaryotic Ribosome Assembly and Export

In eukaryotes, ribosome biogenesis spans three cellular compartments and requires the concerted action of three RNA polymerases, as well as the splicing and nucleocytoplasmic transport machinery. In addition, this process requires >200 trans-acting biogenesis factors, including a range of energy-consuming enzymes and RNA-binding scaffolds that perform both assembly and proofreading functions. Although the mechanisms of ribosome assembly and transport have not yet been fully elucidated, a general framework for this process has emerged from a combination of approaches applied to the organism budding yeast. Here, we review the current state of knowledge of yeast ribosome assembly, quality control, and nuclear export.