Comment on "A G Protein–Coupled Receptor Is a Plasma Membrane Receptor for the Plant Hormone Abscisic Acid"

Abstract
Liu et al . (Reports, 23 March 2007, p. 1712) reported that the Arabidopsis thaliana gene GCR2 encodes a seven-transmembrane, G protein–coupled receptor for abscisic acid. We argue that GCR2 is not likely to be a transmembrane protein nor a G protein–coupled receptor. Instead, GCR2 is most likely a plant homolog of bacterial lanthionine synthetases.