Key component and repressor of the abscisic acid (ABA) signaling pathway that regulates numerous ABA responses, such as stomatal closure, seed germination and inhibition of vegetative growth. Confers enhanced sensitivity to drought. H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Binds 2 magnesium or manganese ions per subunit. Repressed by PYR/PYL/RCAR ABA receptors in an ABA-dependent manner. Interacts with SWI3B (via N-terminus). Interacts with ABA-bounded PYR1, PYL1, PYL2, PYL3, PYL4, PYL5, PYL6, PYL8 and PYL9, and with free PYL2, PYL3, PYL4, PYL10 and PYL13. Mainly cytoplasmic. Expressed in seeds, roots, stems, leaves and flowers, especially in meristematic tissues, guard cells, embryo and siliques. Repressed by MYB44. Induced by ABA. The 'lock' site stabilizes the complex made of PP2C, ABA and PYR/PYL/RCAR receptor by keeping receptor 'gate' and 'latch' loops in closed positions. Belongs to the PP2C family. Truncated N-terminus.