Date Thesis Awarded


Access Type

Honors Thesis -- Access Restricted On-Campus Only

Degree Name

Bachelors of Science (BS)




Oliver Kerscher

Committee Members

Lizabeth Allison

Matthew J. Wawersik

Lisa M. Landino


Slx5 and Slx8 are two subunits of a SUMO-Targeted Ubiquitin Ligase (STUbL) in the budding yeast Saccharomyces cerevisiae. STUbLs are E3 ubiquitin ligases that target sumoylated substrates for ubiquitylation. Slx5 contains several SUMO-interacting motifs (SIMs) and is considered to be the targeting subunit of the Slx5∙Slx8 STUbL. In yeast, Slx5 forms SIM-dependent nuclear foci, some of which co-localize with double-stranded DNA breaks. To study how these foci form in the nucleus, we performed a high-throughput screen for temperature-sensitive mutants. In this screen, we identified an slx5 mutant that both formed nuclear foci and mislocalized to the bud neck. Slx5 localization at the bud neck resembled the localization pattern of septin proteins. Septins are a class of proteins involved in cytokinesis and cellular division and are transiently sumoylated at the G2/M phase of the cell cycle, making them potential Slx5?Slx8 ubiquitylation targets when nuclear import of Slx5 is impaired. Here we present our data and analysis of this Slx5 septin mislocalization phenotype. The findings of this study have great implications for understanding the STUbL activity in humans.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.


Thesis is part of Honors ETD pilot project, 2008-2013. Migrated from Dspace in 2016.

On-Campus Access Only