Abstract
During times of stress, some cells decrease translation of proteins to conserve energy.\r However, cells still need to translate some proteins important for survival in situations of stress.\r To do so, some cells use an internal ribosome entry site, or an IRES, to recruit the ribosome directly\r to the RNA and begin translation. IRESes were first discovered in viruses, and from this we know\r that they are heavily structure dependent. We use a targeted approach to mutagenize the\r mammalian Insulin Receptor (INR) to disrupt the secondary structure and compare translation\r efficiency to the wild-type. Both an in vivo dual luciferase assay, and an in vitro translation assay\r were used to assess the translation efficiency of the mutated and wild-type INR IRESes. While\r there was no observable decrease in translation efficiency of the mutated INR IRES in the in vivo\r dual luciferase assay, we found that there was an observable loss of translation efficiency of the\r mutated INR IRES in the in vitro translation assay. These results suggest that the secondary\r structure of the INR IRES might be important for translation, and that specifically, the area mutated\r is an important structural element of the secondary structure of the INR IRES. Through this study,\r we hope to provide a greater insight into eukaryotic IRESes and their dependence on their\r secondary structure.