Different Xanthines Cause Membrane Potential Oscillations in a Unicellular Green Alga Pointing to a Ryanodine/cADPR Receptor Ca²⁺ Channel

Plant Cell Physiol. 40 (4): 453-456 (1999)

Bauer,C.S., Simonis, W. and Schönknecht, G.

In the unicellular green alga Eremosphaera viridis caffeine induces oscillations of cytosolic Ca²⁺ which cause membrane potential oscillations. Application of the caffeine analogues isocaffeine, theophylline, and isotheophylline resulted in membrane potential oscillations with a structure-activity relationship comparable to isolated ryanodine/cyclic ADPribose (cADPR) receptor Ca²⁺ channels from animal cells.