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

Abstract Ca 2+ ‐ATPases are P‐type ATPases that use the energy of ATP hydrolysis to pump Ca 2+ from the cytoplasm into intracellular compartments or into the apoplast. Plant cells possess two types of Ca 2+ ‐pumping ATPase, named ECAs (for ER‐type Ca 2+ ‐ATPase) and ACAs (for auto‐inhibited Ca 2+ ‐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 Ca 2+ ‐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.