Type of Submission
Poster
Keywords
Tetrahymena, mitotic regulation, gene expression, signal transduction, phosphorylation
Proposal
The Ras/MAPK signaling pathway is a highly conserved mitotic pathway that is is mutated or dysregulated in many cancers. Until recently, Ras was considered “undruggable”, but recently drugs have been designed that would inhibit mitotic signaling through Ras, thus slowing down cancer progression. Our previous work with the Ras-GEF inhibitor, BAY-293 has shown that BAY-293 inhibits mitosis, decreases histone acetylation, and reduces expression of rRNA and mRNA populations in Tetrahymena thermophila. We found that two RNAs, the NgoA RNA and a homologue of the ENO2 gene in yeast, both of which have unknown functions, are differentially regulated in Tetrahymena thermophila that are treated with BAY-293. In our current study, we purified polyadenylated RNA and found that both the ENO2 homolog and the NgoA RNA are polyadenylated. We found evidence that mRNA turnover is greatly increased in cells that have been exposed to BAY-293 for 90 minutes, and that gene expression and signal transduction is altered after 24 hours of exposure to the drug. Using fluorescence microscopy, we found that phosphorylation of MAPK substrates, as well as phosphoserine and phosphotyrosine concentration, were significantly increased by 90-minute exposure to BAY-293, while 24-hour exposure to BAY-293 showed no significant difference in phosphorylation levels between control and drug-treated cells.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Publication Date
2024
Effects of the Ras-GEF Inhibitor, BAY-293, on Gene Expression and Protein Phosphorylation in Tetrahymena Thermophila
The Ras/MAPK signaling pathway is a highly conserved mitotic pathway that is is mutated or dysregulated in many cancers. Until recently, Ras was considered “undruggable”, but recently drugs have been designed that would inhibit mitotic signaling through Ras, thus slowing down cancer progression. Our previous work with the Ras-GEF inhibitor, BAY-293 has shown that BAY-293 inhibits mitosis, decreases histone acetylation, and reduces expression of rRNA and mRNA populations in Tetrahymena thermophila. We found that two RNAs, the NgoA RNA and a homologue of the ENO2 gene in yeast, both of which have unknown functions, are differentially regulated in Tetrahymena thermophila that are treated with BAY-293. In our current study, we purified polyadenylated RNA and found that both the ENO2 homolog and the NgoA RNA are polyadenylated. We found evidence that mRNA turnover is greatly increased in cells that have been exposed to BAY-293 for 90 minutes, and that gene expression and signal transduction is altered after 24 hours of exposure to the drug. Using fluorescence microscopy, we found that phosphorylation of MAPK substrates, as well as phosphoserine and phosphotyrosine concentration, were significantly increased by 90-minute exposure to BAY-293, while 24-hour exposure to BAY-293 showed no significant difference in phosphorylation levels between control and drug-treated cells.
