Positive regulator of hypersensitive response (HR)-like cell death. May be involved in potassium ion channel regulation. Homo- and heterodimer. Interacts with LRR1 (via LRR domain). Constitutively expressed in stems, roots and flowers, but not in leaves and fruits. Up-regulated by pathogens during an incompatible interaction, but not upon infection by a virulent pathogen. Up-regulated by salicylic acid, abscisic acid, ethylene and methyl jasmonate.