Altering Conserved Residues on Dbp5 in S. cerevisiae to Assess Function
Sciences and Mathematics, College of
Biology, Department of
SURS Faculty Advisor
Nuclear mRNA export is essential for the viability of eukaryotic cells as it enables gene expression. This process allows for mRNA, the genetic copy of DNA that encodes for proteins, to be transported from the nucleus, where it is generated, to the cytoplasm for translation. The mRNA transcript requires several binding proteins to cross through nuclear pore complexes (NPC), which are selective doorways embedded in the nuclear envelope. Mex67 is a protein that binds to mRNA, allowing for the transcript to be transported across the nuclear envelope. Once the transcript reaches the cytoplasm, another protein called Dbp5 binds to the mRNA and detaches Mex67 to prevent the mRNA from re-entering the nucleus. Along with Mex67, several other proteins bind to mRNA in the nucleus and remain on the transcript in the cytoplasm. How Dbp5 selectively removes Mex67 and no other RNA binding partners is unknown. Dbp5 has several binding partners, but a patch of conserved amino acids on Dbp5 has previously been identified that is not known to be at interface with known binding partners. This patch having been evolutionarily maintained, indicates that the site likely holds a significant function for cells. I hypothesize that this patch on Dbp5 is at interface with Mex67. In order to test the hypothesis,I generated mutations using site-directed PCR mutagenesis. The mutated plasmids were then confirmed and transformed into S. cerevisiae to assess the mutant Dbp5 functionality. As Dbp5 is essential for cell viability, If this patch of conserved amino acids is essential for mRNA export, the Dbp5 mutants will result in inviable cells. We anticipate that a combination of mutations will reduce Dbp5 functionality, and subsequent experiments will then determine whether the Mex67 interface is disrupted in these mutants.
Ford, Maddy R. and Adams, Rebecca, "Altering Conserved Residues on Dbp5 in S. cerevisiae to Assess Function" (2022). Science University Research Symposium (SURS). 40.