To carry out biological functions, a typical protein must fold into a complex structure encoded by its amino-acid sequence. When DNA mutations or synthesis errors alter that sequence, the protein may misfold, not only losing its function but becoming a toxic, aggregation-prone rogue.
Protein misfolding profoundly shapes organism fitness (including human health): it is a cause of major human diseases, a requirement for proper immune-system function, and a potentially dominant regulator of how rapidly protein-coding genes accumulate sequence changes over evolutionary time. Yet little is known about the major causes, amounts, or consequences of protein misfolding at the scales of whole genomes and organisms. What fraction of newly synthesized proteins misfold, and why? Are some classes of proteins exceptionally robust to mistranslation? If so, what phenotypic consequences result from compromising that robustness?
We are exploring the scope, scale, and causes of protein misfolding and its effects on organism fitness, with a strong focus on newly synthesized proteins. Using the yeast Saccharomyces cerevisiae as a model system, our research combines evolutionary genomics, which reveals broad patterns of fitness imprinted in DNA, with system- and molecular-level misfolding studies designed to illuminate the conserved biochemistry underlying these patterns.
May 3, 2009: We lost a wonderful colleague and friend today. Our hearts go out to her family; she was part of ours.