Date of Award
Bachelor of Science
The central dogma of cellular biology asserts that DNA is transcribed to mRNA, which in turn is translated to a protein. This simplistic conduit of gene expression is heavily regulated at multiple levels to ensure proper temporal and spatial expression of genes. One such mode of regulation occurs at the juncture at which RNAs are translated to proteins, known as translational regulation. mRNAs can be translationally regulated by trans-acting factors, such as RNA binding proteins (RBPs), and/or cis-acting factors. Regulation via these two modalities can depend on structure as well as RNA sequence. Secondary structures, such as stem loops, are unique motifs that can be recognized by RBPs. To study the influence of structure on translational regulation, we used the polar granule component (pgc) of Drosophila melanogaster as a model mRNA. It has been shown that the 3’untranslated region (UTR) of pgc is sufficient to temporally and spatially regulate the mRNA throughout development. Secondary structure analysis via RNA footprinting showed that pgc forms a unique and stable secondary structure. By utilizing a GFP reporter that is expressed under the control of a pgc 3’UTR, we sequentially explored the influence these structures had on pgc translation. We found that a stem loop, SL10, when deleted resulted in a loss of somatic translational control during embryogenesis. To elucidate the mechanism by which SL10 influences translational regulation of pgc we established an in vitro dimerization assay, which showed that cis-acting interactions are possible. This form of interaction could suggest that two or more pgc mRNAs interact to potentially occlude the mRNA from active translation. Further in vivo and in vitro studies are needed to identify the role that SL10 plays in translation control, with it being either a dimerization motif, or a putative binding site for RBPs.
Patel, Dhruv S., "Determining the role of secondary structure in translational control" (2017). Chemistry. 8.