Ethylene receptor related to bacterial two-component regulators. Acts as negative regulator of ethylene signaling. May delay the transition from the vegetative stage to the floral stage by up-regulating GI (GIGANTEA) and RCN1 and cause starch accumulation in stems by down-regulating the alpha-amylase AMY3D. ATP + protein L-histidine = ADP + protein N-phospho-L-histidine. Binds 1 copper ion per dimer. Expressed in anthers and hulls. By ethylene and auxin (PubMed:14754915). Induced by submergence, ethylene and gibberellin (PubMed:15020633). Belongs to the ethylene receptor family.