Seminar offered on genome stability

Monday, June 29, 3-4 p.m.
UAA Consortium Library, Room 307

Dr. Steven Brill, Rutgers University professor from the Department of Molecular Biology and Biochemistry, will speak Monday, June 29 from 3-4 p.m. in UAA Consortium Library, Room 307. His topic: "Genetic analysis of genome stability in yeast identifies an unexpected role for SUMO."

Here is a summary of the seminar:

The human Bloom Syndrome protein is important for the suppression of hyper-recombination and is conserved in budding yeast as Sgs1. In a previous screen for genes that are essential for viability in the absence of Sgs1, we identified several conserved proteins required for the maintenance of genome stability.

One of these, Slx5-Slx8, is a novel Ub ligase complex that ubiquitinates proteins bearing the protein modifier SUMO. Biochemical analysis of its preferred substrate suggests that Slx5-Slx8 preferentially ubiquitinates proteins that are poly-sumoylated so as to mark them for proteasomal destruction. And recent genetic analysis has led to the identification of a new SUMO isopeptidase that also acts in this pathway. Studies of the isopeptidase suggest that elimination of the poly-SUMO chain may be the overall goal of this pathway. The results not only link ubiquitination to the SUMO pathway, but suggest that poly-sumoylation is a previously unappreciated regulator of genome stability.