Structure and function analysis of a CC-NBS-LRR protein AT1G12290.

Nucleotide-binding site (NBS) and leucine-rich repeat (LRR) receptors (NLRs) play important roles in plant immunity. The genome of Arabidopsis thaliana contains about 150 genes encoding NLR proteins, but few of them have been studied. We transiently expressed a series of NBS-LRR proteins in the leaves of Nicotiana benthamiana, and found that the CC-NBS-LRR protein (AT1G12290) was able to trigger cell death, a characterized function for the activation of an NLR protein. We observed that the YFP-tagged AT1G12290 was localized on the plasma membrane (PM), and the predicted myristoylation site Gly2 is required for the localization and function of the protein. Further structure dissection revealed that the CC domain was enough to activate cell death, and the N-terminal 1-100 amino acid fragment was the minimal region to induce cell death and self-association. Our research provides important clues to elucidate the activation mechanism of AT1G12290.