1. The role of UBA4 in the genome of the yeast Saccharomyces cerevisiae
David Roberts, Claire Romelfanger, George Sprague PhD,
Morehouse College, Atlanta GA, University of Oregon, Eugene OR

2. Saccharomyces cerevisiae
Easy to culture
-Eukaryotic cells similar in complexity to plant and animal cells
Reproduce sexually and asexually
Exists in haploid and diploid states
-70% of the genome well elucidated

4. UBA4 Known functions of UBA4
UBA4 is a critical enzyme in the process of urmylation. Urmylation is involved in the following processes
Urm1 activating enzyme (urmylation)
Cell budding
Invasive growth
Psuedohyphal growth
Response to oxidative stress
Why study UBA4?
UBA4 is present in all eukaryotic organisms
-To establish the specific role of urmylation in its processes
-To establish UBA4 functioning beyond urmylation
Objective of study:
-To gain further insight into the genetic interactions of UBA4

5. Ubiquitination and Urmylation
Uba4 ?
Uba1 E1
Activating Enzyme E2
Conjugating Enzyme
Ubc4 E3
Protein Ligase
Ubr2
Ubiquitin Protease
UBP2

6. Synthetic Genetic Analysis
UBA4
Approximately 5000 single gene deleted mutants
uba∆
YFG
yfg∆
Synthetic Sick
Synthetic Lethal
Healthy

7. Synthetic lethal mutant
Results
Synthetic sick mutant
Synthetic lethal mutant
Plate of mutants
Synthetic Sickness and Lethality
Mutants said to be synthetically sick demonstrated diminished growth when compared to healthy growing (wild type) mutants.
Synthetically lethal mutants demonstrated no growth when compared to wild type mutants.

8. UBA4 synthetic lethal/sick genes sorted by function
Signal Transduction
Cell Organization and Biogenesis
Protein Degredation
Metabolism
Transcription
RNA Processing
Transport
Unknown
DNA Repair
DNA Metabolism
Protein Transport

9. UBA4 synthetic lethal/sick genes that overlap with URM1 synthetic lethal/sick genes
Cell organization and biogenesis
Protein Transport
Unknown
Signal Transduction
Protein synthesis
Metabolism

10. Conclusions
The results suggest that UBA4 genetically interacts with 56 different genes which participate in the following cellular processes:
-transport
-cell organization and biogenesis
-transcription
-RNA processing
-DNA repair
-DNA metabolism
-protein transport
-protein degradation
-signal transduction
-metabolism
Furthermore 12 of these genes are known to be synthetically lethal or sick with urm1∆, suggesting that urmylation may be involved in the processes governed by these genes.

11. Projections for Further Study
Subsequent synthetic genetic analysis trials must be conducted to determine whether or not the results obtained in this experiment are reproducable.
Random spore analysis must be conducted to verify the existence of the genetic interactions believed to have been observed.

12. Acknowledgements Spur Program Sprague Lab Students Coordinators
Claire Romelfanger
Charles Kubicek
Kimberly Landreth
Steven Tersigni
Dr. George Sprague