Belmont University Research Symposium (BURS)

Publication Date

Spring 3-29-2024

College

Sciences and Mathematics, College of

Department

Biology, Department of

BURS Faculty Advisor

Rebecca Adams

Presentation Type

Poster Presentation

Abstract

For proper gene expression in eukaryotes, mRNA export from the nucleus to the cytoplasm for protein synthesis. This process is aided by the binding of a protein called Mex67 to the transcript, to allow for the mRNA to transport through the nuclear pore complex (NPC), selective doorways embedded in the nuclear envelope. Mex67 is recruited to mature mRNA via interaction with adaptor proteins such as Nab2, which signals the proper addition of the poly-A tail. Once the transcript reaches the cytoplasmic side of the NPC, Mex67 and Nab2 are removed by the enzyme Dbp5, which binds to RNA to induce local proteins to fall off the transcript. Indeed, previous studies have observed that a mutant of Dbp5 that cannot bind RNA (Dbp5R369G) results in cell lethality via a dominant-negative mechanism in S. cerevisiae. Importantly, other RNA binding proteins that interact with the transcript are not removed by Dbp5, and the mechanism of Dbp5 specificity is not understood. We hypothesize that Dbp5 may interact with either Mex67 or Nab2, to recruit Dbp5 binding to the region mRNA where they bind and thus allow for their selective removal. Furthermore, we anticipate that Dbp5R369G lethality is due to Lack of Mex67 and/or Nab2 removal and recycling for additional rounds of mRNA export. To test this hypothesis, we sought to overexpress Nab2 in the presence of Dbp5R369G, anticipating that increased Nab2 concentration in the cell will bypass lethality. Therefore, my work has been aimed at generating a plasmid that contains the Nab2 gene under the expression of the galactose-responsive promoter. Following my successful generation of this plasmid, I transformed yeast with both Gal-Dbp5R369G and Gal-Nab2 plasmids. Future work is aimed at assessing the viability of the resulting yeast strains.

Download

Share

COinS