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Repetitive Ca 2+ spikes in a unicellular green alga
Author(s) -
Bauer C.S.,
Plieth C.,
Hansen U.-P.,
Sattelmacher B.,
Simonis W.,
Schönknecht G.
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)00231-7
Subject(s) - biophysics , hyperpolarization (physics) , chemistry , membrane potential , cytosol , intracellular , biochemistry , biology , stereochemistry , nuclear magnetic resonance spectroscopy , enzyme
Cytosolic Ca 2+ activity ([Ca 2+ ] cy ) and membrane potential were measured simultaneously in the unicellular green alga Eremosphaera viridis . Steady state [Ca 2+ ] cy was about 160 nM. A ‘light‐off’ stimulus induced a transient elevation of [Ca 2+ ] cy ([Ca 2+ ] cy spike) in parallel with a transient hyperpolarization of the plasma membrane. Caffeine and Sr 2+ , known to release Ca 2+ from intracellular stores in animal cells, induced repetitive [Ca 2+ ] cy spikes in Eremosphaera which were always accompanied by parallel repetitive transient hyperpolarizations. These transient hyperpolarizations could be used as an indicator for [Ca 2+ ] cy spikes. Repetitive [Ca 2+ ] cy spikes in Eremosphaera were similar to repetitive [Ca 2+ ] cy spikes in excitable animal cells. The mechanisms underlying these [Ca 2+ ] cy oscillations seem to be comparable in animal and plant cells.