Ca signals triggered by bacterial pathogens and microdomains.

Recent reports have highlighted the pivotal role of Ca during host cell infection by bacterial pathogens. Here, we review how bacterial pore-forming toxins (PFTs) trigger global Ca signals to regulate cell adhesion-, inflammatory- or death processes. We comment recent reports describing the role of bacterial effectors injected by a type III secretion system (T3SS) as well as host cell players in the formation of Ca microdomains during Shigella invasion and Chlamydia extrusion of host cells. We discuss how modeling and comparison between bacterial-induced and physiological Ca microdomains provides insight into the critical parameters shaping the duration of local Ca responses.