The innate immune response is the body's first line of defense against pathogen infection. Dr. Xin Li (University of British Columbia) and colleagues report that three proteins work together in the MOS4-associated complex (MAC) to execute innate immunity in the mustard weed, Arabidopsis.
Dr. Li and colleagues study a plant autoimmune model in which a mutation in one immune receptor, SNC1, causes constitutive activation of the plant's immune response. Dr. Li's group found that 3 key downstream effectors of the SNC1 pathway -- MOS4, AtCDC5 and PRL1 -- are homologous to components of the human spliceosome-associated nineteen complex (NTC). The researchers speculate that the evolutionarily conserved NTC may also play a role in animal innate immunity.
"Our work is further evidence that the little plant Arabidopsis remains a very robust genetic tool for dissecting processes in multicellular eukaryotes, with relevance to the realm of human biology. To our knowledge, this is the first placement of the NTC into a known signaling pathway in any organism. We are continuing to find commonality between animal and plant innate immunity at the level of both receptors and signalling intermediates; the complex we describe, essential for plant innate immunity, may be another example of this."