| Description |
Proteins are life's double edged sword. Proteins are essential macromolecules of life, and the tasks that some proteins accomplish are quite marvelous. At the same time, if proteins misfold they have the potential to kill the cell that harbors them. It is becoming increasingly clear that proteins have the potential to misfold from the very beginning of their life, during translation. To strike a balance between translational efficiency and accuracy, cells choose between various synonymous codons to regulate translation. Frequent codons are translated more quickly than rare codons, and the usage of frequent and rare codons is used to regulate translation dynamics. The balance between the usage of frequent and rare codons is fine, as synonymous mutations can disrupt the translational machinery enough to abort translation and degrade the nascent protein. Surprisingly, disruption of the ribosome happens quite frequently, and requires the response of ribosome associated quality control (RQC) to degrade the potentially misfolded proteins. So far only one RQC pathway has been described that responds to ribosomes that have been stalled for prolonged periods of time. In this study I present a novel RQC pathway where the ribosome is able to recover from stalling. Despite ribosome recovery, the nascent protein is still targeted for degradation with ubiquitin. I found that previously described RQC components, Ltn1 and Rqc1 are involved in this pathway. Additionally, I begin to characterize how the nascent protein is trafficked from the ribosome to the vacuole. This new RQC pathway further highlights the importance codon usage plays in protein folding and adds a more nuanced view of the genetic code and translation. |
