Summary: Research Roundup
JCB · VOLUME 171 · NUMBER 1 · 200510
Highly goes slowly
ates of protein evolution vary widely.
Very little of this variation is explained
by dispensability (essential proteins
evolving slowly), but up to a third is explained
by expression levels. For an entirely mysterious
reason, highly expressed proteins evolve slowly.
Now, Allan Drummond and colleagues
(Caltech, Pasadena, CA; and Keck Graduate
Institute, Claremont, CA) argue that this corre-
lation is based on the severe selective pres-
sure on highly expressed proteins to avoid
misfolding even when they are mistranslated.
More abundant proteins are a greater mis-
folding threat because even a low misfolding
rate would result in many misfolded, poten-
Pressure not to misfold means that higher