The role of UBA4 in the genome of the yeast Saccharomyces cerevisiae http://www.chateauneuf.dk/artikler/vini15.jpg David Roberts, Claire Romelfanger, George Sprague PhD, Morehouse College, Atlanta GA, University of Oregon, Eugene OR

Saccharomyces cerevisiae http://www.chateauneuf.dk/artikler/vini15.jpg http://www.science.lsus.edu/documents/resume/94859/yeast3.jpg 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

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

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

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

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.

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

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

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.

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.

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