Life in a low calcium home

Life without Ca²⁺—a vital enzyme cofactor and essential second messenger—is no life at all. Consider then the challenge faced by Plasmodia, the causal agent of malaria. These parasites spend most of their life inside red blood cells, whose cytoplasmic levels of Ca²⁺ are far too low to support their survival. On page 103, Gazarini et al. now show that Plasmodia get around this problem by maintaining a high Ca²⁺ level within the parasitophorous vacuole (PV), their home in the red blood cell.

Previous studies suggested that the PV membrane (PVM) was something of a sieve, and that the ionic environment inside it should be similar to the host cytoplasm. The researchers tested this by using indicator dyes to measure Ca²⁺ levels in...