Undergraduate (Math/EEB/Physics major)
Ph. 520 626 1727
Office: BSW122
I am looking for backup stop codons as a signal of preadaptation in Saccharomyces 3′ UTRs.
The machinery which controls translation termination is not perfect; sometimes, a ribosome will translate these supposedly “untranslated” regions. This means that additional amino acids will be attached to a growing peptide. The protein’s ultimate function is more likely to be catastrophically impacted if the number of additional amino acids is large.
We predict that low levels of readthrough translation permit selection on 3′ UTR content. One signal of this low-level selection is the presence of close backup stop codons which give the ribosome a second chance to terminate translation. Close backup stops minimize the number of additional amino acids; this lessens the chance of ruining the nascent peptide. Sometimes, small numbers of additional amino acids might even “tweak” the protein, improving its function.
I am using a combination of bioinformatic and comparative genomic approaches to look for backup stops. If preadaptation is occurring in yeast 3′ UTRs, then backup stops should be closer than predicted by random chance and the genomic background, and they should also be conserved during evolution. I’m also developing ways to discern which genes are being most affected by this process.
Low-level leaky readthrough is not unique to yeast, so these results may appear in other organisms with sufficiently large population size, as well. What makes Saccharomyces unique is the presence of [PSI], an epigenetically inherited prion which increases readthrough a few fold. This causes the once-cryptic 3′ UTR data to “flash” to an active state. If the 3′ UTR data is adaptive, then natural selection may favor a removal of the first stop codon. Preadaptation thus provides strong evidence that [PSI] plays a role in evolvability.
Other research interests of mine are in theoretical population genetics and evolutionary theory. When I am not in the lab, I enjoy weightlifting, practicing my Swedish, and cooking spartan meals. I have amateur interests in politics, philosophy (especially meta-ethics), the conflict between science and extremist religion, and physics.