Vacuolar Ca2+ uptake

Calcium transporters that mediate the removal of Ca2+ from the cytosol and into internal stores provide a critical role in regulating Ca2+ signals following stimulus induction and in preventing calcium toxicity. The vacuole is a major calcium store in many organisms, particularly plants and fungi. Two main pathways facilitate the accumulation of Ca2+ into vacuoles, Ca2+-ATPases and Ca2+/H+ exchangers. Here I review the biochemical and regulatory features of these transporters that have been characterised in yeast and plants. These Ca2+ transport mechanisms are compared with those being identified from other vacuolated organisms including algae and protozoa. Studies suggest that Ca2+ uptake into vacuoles and other related acidic Ca2+ stores occurs by conserved mechanisms which developed early in evolution.