Description:

"RACK1 Evolved Species-Specific Multifunctionality in Translational Control Though Sequence Plasticity in a Loop Domain"

Speaker: Madelline Rollins, Driskill Graduate Program, Lab of Derek Walsh, PhD

TOPIC

The ability to regulate translation rates of individual mRNAs enables cells to rapidly adjust the levels of specific proteins during a wide range of processes. Viruses have also evolved mechanisms to tune cellular translation efficiency to enhance viral protein production, which can be achieved by manipulating ribosomal protein expression and post-translational modifications as well as ribosome activity. Through this “ribosome specification,” changes in ribosome composition and subsequent recognition of specific RNA elements may extend an additional level of control over protein synthesis. We have recently found that the poxvirus Vaccinia virus (VacV) phosphorylates a C-terminal extended loop of the core small ribosomal protein, RACK1. This modification enhances the translation of poxviral transcripts with unusual 5’UTR polyA leaders. Using both phylogenetic and biochemical approaches, we expand on our previous findings to show that sequence plasticity of the loop enables RACK1 to control ribosome assembly and translational specification in different species.