Poster abstracts
Poster number 141 submitted by Rheanna Walther
Mutation of C. albicans snR10c leads to translational inhibitor sensitivity
Rheanna E. Walther (Biology Department, Ball State University ), Douglas A. Bernstein (Biology Department, Ball State University )
Abstract:
Candida albicans is a dimorphic opportunistic fungal pathogen that causes infections ranging in severity from superficial skin and mucosal surface infections to organ and blood infections. Due to its prevalence as a pathogen, it is important to understand what distinguishes C. albicans from mammals at a molecular level. Pseudouridine is found in all species and understanding pseudouridine synthesis in C. albicans may help us better understand the process in other species and/or potentially serve as a therapeutic target. Some pseudouridine synthases are guided to their substrates by H/ACA box snoRNAs. snR3a, snR10b, and snR10c are three C. albicans H/ACA snoRNAs predicted to target rRNA residue 2919 of the large subunit. We modified the targeting region of C. albicans snR3a, snR10b, and snR10c using CRISPR-Cas9 genome editing so that they could no longer target rRNA. We find that the alteration of snR3a at its binding site eliminates modification of uridine 2919 of cells grown in nutrient-rich media (YPD) at 30°C. Conversely, we find that alteration of snR10b and snR10c has no impact on pseudouridylation at residue 2919. This suggests that snR10b and snR10c are nonessential for pseudouridylation under our tested conditions. We next tested if our modified snoRNA strains displayed altered growth. We find 2 mutant isolates of snR10c that have additional insertion and point mutations downstream of the annotated snoRNA gene result in sensitivity to translation inhibitors. RNA seq data suggests these downstream regions are transcribed. These findings suggest that snR10c is longer than annotated and these extended regions are important for growth and filamentation under translational stress.
Keywords: snoRNA, Candida albicans, pseudouridine