Mediates the transient calcium-dependent interaction of PYR/PYL/RCAR abscisic acid (ABA) receptors with the plasma membrane and thus regulates ABA sensitivity (PubMed:26719420, PubMed:25465408). Stimulates the GTPase/ATPase activities of YchF1, and regulates its subcellular localization. Promotes tolerance towards salinity stress by limiting the accumulation of reactive oxygen species (ROS) (PubMed:23550829). Promotes resistance to bacterial pathogens (e.g. Xanthomonas oryzae pv. oryzae and P. syringae pv. tomato DC3000) (By similarity). Binds liposomes in the absence of exogenous Ca(2+), but this activity is enhanced in the presence of Ca(2+) and generates membrane curvature (PubMed:26719420). Dimers and oligomers (PubMed:26719420). Binds to PYR/PYL/RCAR abscisic acid intracellular receptors in an ABA-independent manner, both at the plasma membrane and in the nucleus (PubMed:25465408, PubMed:26719420). Interacts directly with PYR1, PYL1, PYL4, PYL6 and PYL8 (PubMed:25465408, PubMed:26719420). Binds phospholipids in a Ca(2+)-dependent manner (PubMed:25465408). Interacts with YchF1 (PubMed:23550829). Localized mainly in the cytosol under NaCl treatment, but translocates to the plasma membrane upon wounding. When associated with disruption in CAR1, CAR5 and CAR9 genes, reduced sensitivity to abscisic acid (ABA) during seedling establishment and root growth regulation. Belongs to the plant CAR protein family.