摘要
Calcineurin(CN)is a calcium-and calmodulindependent serine/threonine that has been studied in many model organisms including yeast,filamentous fungi,plants,and mammals.Its biological functions range from ion homeostasis and virulence in lower eukaryotes to T-cell activation in humans by human nuclear factors of activated T-cells.CN is a heterodimeric protein consisting of a catalytic subunit,calcineurin A(Cna1p),which contains an active site with a dinuclear metal center,and a regulatory Ca^(2+) binding subunit called calcineurin B(Cnb1p)required to activate Cna1p.The calcineurin B subunit has been highly conserved through evolution:For example,the mammalian calcineurin B shows 54%identity with calcineurin B from Saccharomyces cerevisiae.
