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Calcium regulation in endosymbiotic organelles of plants
01.09.2009
In plant cells calcium-dependent signaling pathways are involved
in a large array of biological processes in response to hormones,
biotic/abiotic stress signals and a variety of developmental cues.
This is generally achieved through binding of calcium to diverse
calcium-sensing proteins, which subsequently control downstream
events by activating or inhibiting biochemical reactions.
Regulation by calcium is considered as a eukaryotic trait and
has not been described for prokaryotes. Nevertheless, there is
increasing evidence indicating that organelles of prokaryotic origin,
such as chloroplasts and mitochondria, are integrated into the
calcium-signaling network of the cell. An important transducer
of calcium in these organelles appears to be calmodulin. In this
review we want to give an overview over present data showing
that endosymbiotic organelles harbour calcium-dependent biological
processes with a focus on calmodulin-regulation.
