Related Experiment Video
Updated: Aug 14, 2026

Live Imaging Assay for Assessing the Roles of Ca2+ and Sphingomyelinase in the Repair of Pore-forming Toxin Wounds
Published on: August 25, 2013
Staphylococcus aureus alpha-toxin activates phospholipases and induces a Ca2+ influx in PC12 cells
D Fink1, M L Contreras, P I Lelkes
1Section on Growth Factors, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
Abstract:
Staphylococcal alpha-toxin at subcytotoxic concentrations stimulated phosphatidylinositol turnover and arachidonic acid release in undifferentiated cultures of pheochromocytoma PC12 cells. Stimulation of phospholipase A2 but not C was dependent on extracellular calcium. Addition of staphylococcal alpha-toxin to PC12 cells caused a dose-dependent, biphasic increase in intracellular calcium measured by fura-2 fluorescence technique. Elevation of intracellular Ca2+ content occurred with a time course similar to those observed for stimulation of phospholipase A2. Alteration of membrane structure and formation of staphylococcal alpha-toxin pores facilitating an influx of Ca2+, represent the probable mechanisms by which phospholipases C and A2 are activated, respectively. These results suggest a possible involvement of Ca2+, phosphoinositides and arachidonic acid metabolites in the pathogenic action of staphylococcus alpha-toxin and caution against the general usage of this toxin as a permeabilizing agent to study stimulus-secretion coupling in secretory cells.
Related Concept Videos
Amplifying Signals via Second Messengers
GPCRs Regulate Adenylyl Cylase Activity
Two...
IP3/DAG Signaling Pathway
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Bacterial Toxins

