InterPro domain: IPR014525

This entry represents hybrid ethylene sensor histidine kinases from plants, also known as ethylene receptors. It includes ETR1, ETR2, and EIN4 from Arabidopsis thaliana, all of which contain a receiver domain at the C terminus. ETR1 has His kinase activity, whereas ETR2 and EIN4 have Ser/Thr kinase activity [ 1 ]. They are related to bacterial two-component regulators and act as a redundant negative regulator of ethylene signalling [ 2 ].

1. Ethylene Receptors Signal via a Noncanonical Pathway to Regulate Abscisic Acid Responses. Plant Physiol. 176, 910-929
2. Ethylene-binding activity, gene expression levels, and receptor system output for ethylene receptor family members from Arabidopsis and tomato. Plant J. 41, 651-9