The plant Ca2+-ATPase repertoire: biochemical features and physiological functions

Ca2+-ATPases are P-type ATPases that use the energy of ATP hydrolysis to pump Ca2+ from the cytoplasm into intracellular compartments or into the apoplast. Plant cells possess two types of Ca2+-pumping ATPase, named ECAs (for ER-type Ca2+-ATPase) and ACAs (for auto-inhibited Ca2+-ATPase). Each type comprises different isoforms, localised on different membranes. Here, we summarise available knowledge of the biochemical characteristics and the physiological role of plant Ca2+-ATPases, greatly improved after gene identification, which allows both biochemical analysis of single isoforms through heterologous expression in yeast and expression profiling and phenotypic analysis of single isoform knock-out mutants.