Protein that affects susceptibility to anthrax

Individual mouse strains exhibit striking differences in the susceptibility of their macrophages to the cytolytic effects of anthrax lethal toxin (LeTx), but the causes of these variations remain unknown. In October Current Biology, James Watters and colleagues from Harvard Medical School, Boston, show that Kif1C, a kinesin-like motor protein, is responsible for the differences in susceptibility to anthrax and protects macrophages from LeTx (Current Biology 2001, 11:1503-1511).

Watters et al. found that Kif1C is the only gene that exhibits polymorphisms between susceptible and resistant strains of mice. Treatment of resistant macrophages with brefeldin-A (which alters the cellular localization of Kif1C) induces susceptibility to LeTx, while ectopic expression of a resistance allele of Kif1C in susceptible macrophages causes a 4-fold increase in the number of cells surviving LeTx treatment.

In addition, they showed that cleavage of map kinase kinase 3 — a target of LeTx proteolysis —...