A link of Ca2+ to cAMP oscillations in Dictyostelium : the calmodulin antagonist W-7 potentiates cAMP relay and transiently inhibits the acidic Ca2+-store
2004-05-17, Malchow, Dieter, Lusche, Daniel F., Schlatterer, Christina
During early differentiation of Dictyostelium the attractant cAMP is released periodically to induce aggregation of the cells. Here we pursue the question whether pulsatile cAMP signaling is coupled to a basic Ca2+-oscillation.
The contractile vacuole in Ca2+-regulation in Dictyostelium : its essential function for cAMP-induced Ca2+-influx
2006, Malchow, Dieter, Lusche, Daniel F., Schlatterer, Christina, De Lozanne, Arturo, Müller-Taubenberger, Annette
cAMP-induced Ca2+-influx in Dictyostelium is controlled by at least two non-mitochondrial Ca2+-stores: acidic stores and the endoplasmic reticulum (ER). The acidic stores may comprise the contractile vacuole network (CV), the endosomal compartment and acidocalcisomes. Here the role of CV in respect to function as a potential Ca2+-store was investigated.
Ca2+ regulation in the absence of the iplA gene product in Dictyostelium discoideum
2005, Schaloske, Ralph H., Lusche, Daniel F., Bezares-Roder, Karen, Happle, Kathrin, Malchow, Dieter, Schlatterer, Christina
Stimulation of Dictyostelium discoideum with cAMP evokes an elevation of the cytosolic free Ca2+ concentration ([Ca2+]i). The [Ca2+]i-change is composed of liberation of stored Ca2+ and extracellular Ca2+-entry. The significance of the [Ca2+]i-transient for chemotaxis is under debate. Abolition of chemotactic orientation and migration by Ca2+-buffers in the cytosol indicates that a [Ca2+]i-increase is required for chemotaxis. Yet, the iplA- mutant disrupted in a gene bearing similarity to IP3-receptors of higher eukaryotes aggregates despite the absence of a cAMP-induced [Ca2+]i-transient which favours the view that [Ca2+]i-changes are insignificant for chemotaxis.