Plutonium poisoning

Insight into how cells in the body take up the radioactive element plutonium is provided in a paper published this week in Nature Chemical Biology. Given the recent damage to the Fukushima nuclear reactors in Japan and the use of plutonium-containing fuels in nuclear reactors outside of Japan, this study may help scientists explore strategies to minimize the uptake of plutonium by human cells exposed to plutonium contamination in the environment.

Plutonium is a largely manmade element that is toxic to humans. It was suspected that plutonium, which shares some chemical characteristics with iron, can be taken up by the same pathways that cells use to acquire the mineral nutrient.

Mark Jensen and colleagues demonstrate that this is indeed the case, but with one important caveat. The transporter protein that carries iron into cells can only enter cells if both lobes of the protein, which contain the iron-binding sites, can close. Unexpectedly, only one of these lobes can close upon binding to plutonium, so the cellular uptake of plutonium requires assistance from iron binding to the other lobe.