Poster abstracts

Poster number 62 submitted by Jazmin Marks-Burns

Investigating the effects of PUS5 deletion on mitochondrial encoded protein expression in Candida albicans and Saccharomyces cerevisiae

Jazmin L Marks-Burns (Biology, Ball State University), Ally R. Morris (Biology, Ball State University), Douglas A. Bernstein (Biology, Ball State University)

Abstract:
While RNA is made of only 4 bases, these bases can be modified in over 100 distinct ways. These modifications play critical roles in modulating RNA function. Pseudouridine is the most common modified nucleoside, and is found in all kingdoms of life. However, the role of pseudouridylation in translation and RNA function is not well understood. Pseudouridylation is found at dozens of sites in Eukaryotic cytoplasmic rRNA and cytoplasmic ribosomes translate thousands of proteins. As such, it is challenging to study the effects individual sites of pseudouridylation have on translation. In contrast, in fungi, mitochondrial ribosomes translate only eight proteins encoded by the mitochondrial genome and mitochondrial rRNA contains only one highly conserved pseudouridine, which is made by the pseudouridine synthase Pus5. I find Saccharomyces cerevisiae pus5Δ deletion is more sensitive to drugs that inhibit oxidative phosphorylation such as oligomycin, suggesting they have a defect in mitochondrial function. I hypothesize Pus5 mediated pseudouridylation is important for mitochondrial protein expression. I will use mass spectrometry to determine if mitochondrial rRNA pseudouridylation is required for wild type mitochondrial gene translation. Furthermore, from this mass spectrometry data, I will determine if C. albicans uses an alternative mitochondrial genetic code. Investigation of this highly conserved RNA modification will lead to a better understanding of how defects in pseudouridylation lead to human disease and could lead to the identification of novel antifungal drug targets.

References:
Ansmant, I., Massenet, S., Grosjean, H., Motorin, Y., & Branlant, C. (2000). Identification of the Saccharomyces cerevisiae RNA: pseudouridine synthase responsible for formation of Ψ2819 in 21S mitochondrial ribosomal RNA. Nucleic acids research, 28(9), 1941-1946.
Banks, C.A., S.E. Kong, and M.P. Washburn, Affinity purification of protein complexes for analysis by multidimensional protein identification technology. Protein expression and purification, 2012. 86(2): p. 105-119.
Miranda, I., et al., A genetic code alteration is a phenotype diversity generator in the human pathogen Candida albicans. PLoS One, 2007. 2(10): p. e996
Spenkuch, F., Y. Motorin, and M. Helm, Pseudouridine: still mysterious, but never a fake (uridine)! RNA biology, 2014. 11(12): p. 1540-1554.

Keywords: pseudouridlyation, Candida albicans, mitochondrial rRNA