Disease resistance protein that mediates defense responses against the bacterial pathogen Pseudomonas syringae pv tomato strain DC3000, and the virulent oomycete Hyaloperonospora arabidopsidis isolate Noco2. Becomes active when the MEKK1-MKK1-MKK2-MPK4 kinase cascade is disrupted by the microbial effector hopAI1. Does not seem to be required for the activation of MPK4 by flg22, or flg22-induced up-regulation of PAD3 (PubMed:22423965). Functions downstream of MEKK2/SUMM1 in immune responses, including cell death and defense responses (PubMed:22643122). Negatively regulated by the MEKK1-MKK1-MKK2-MPK4 kinase cascade. Interacts with PAT1. The LRR repeats probably act as specificity determinant of pathogen recognition. Belongs to the disease resistance NB-LRR family. Functional and comparative genomics of disease resistance gene homologs