At MIT Varshavsky, Ciechanover, and graduate student Dan Finley set out to determine whether the mutant hamster cells had a defect in the Hershko / Ciechanover ubiquitin relay.
In all ubiquitination previously observed, the cascade of three E enzymes performed a sort of relay in which one activated a ubiquitin protein, one transferred it to the target protein and one attached it, he said.