Professor’s work described in a prestigious Proceedings of the National Academy of Sciences (USA) publication

Posted On May 11, 2013
Categories Department News

When two proteins differ just by one electron, what would be the structural consequence? Recently, a graduate student, Ms. Fange (Katherine) Liu, a graduate student in the Department of Chemistry, College of Arts and Sciences, has provided a remarkable answer. The human nuclear iron protein Pirin is present in all tissues but its biological function was unknown until a new paper in Proceedings of the National Academy of Sciences (USA) describing Ms. Liu’s work. In its resting ferrous (Fe2+) state, Pirin is predictably inactive. Upon stimulation and oxidative stress, however, the oxidized ferric (Fe3+) Pirin changes its structure and binds to the transcriptional factor NF-κB proteins. The resulting protein complex binds and activates specific stress-related genes to initiate anti-oxidative signaling cascades. The ferric Pirin has just one more electron than the ferrous Pirin, yet over 22% of the total 290 amino acids change conformations at one side of the protein and thus Pirin becomes activated in signaling transduction. The function of Pirin is not only illuminated by the dissertation work of Ms. Liu and her fellow colleagues in Dr. Aimin Liu’s laboratory, the regulation mechanism to the primary signal transduction signaling is also revealed, and yet, it is surprisingly simple, elegant, and efficient.
Ms. Liu is a graduate fellow of the Center for Diagnostics and Therapeutics (CDT). The Liu Lab in the Department of Chemistry and CDT has recently made a few strides in the metalloprotein and free radical research field (, resulting in three consecutive publications in the National Academy of Sciences’ journal known as PNAS this spring through direct submissions. The story highlighted above is one of them and it has the promise to fuel future breakthroughs in the fields of metalloprotein-based sensors and signal transduction regulations.