Cleavage and nuclear localization of the rice XA21 immune receptor

• Published in: Nature communications Vol. 3; no. 1; p. 920
• Main Authors: Park, Chang-Jin, Ronald, Pamela C.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26.06.2012; Nature Publishing Group; Nature Pub. Group
• Subjects: 631/449/2169; 631/449/2675; Cell Nucleus - genetics; Cell Nucleus - metabolism; Humanities and Social Sciences; Immune response; multidisciplinary; Oryza - genetics; Oryza - metabolism; Oryza - microbiology; Pathogens; Plant Immunity - genetics; Plant Immunity - physiology; Plant Proteins - genetics; Plant Proteins - metabolism; Science; Science (multidisciplinary); Xanthomonas - pathogenicity
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms1932

Plants and animals carry specific receptors that recognize invading pathogens and respond by activating an immune response. The rice XA21 receptor confers broad-spectrum immunity to the Gram-negative bacterial pathogen, Xanthomonas oryzae pv. oryzae upon recognition of a small protein, Ax21, that is conserved in all Xanthomonas species and related genera. Here we demonstrate that XA21 is cleaved to release the intracellular kinase domain and that this intracellular domain carries a functional nuclear localization sequence. Bimolecular fluorescence complementation assays indicate that the XA21 intracellular domain interacts with the OsWRKY62 transcriptional regulator exclusively in the nucleus of rice protoplasts. In vivo cleavage of XA21 and translocalization of the intracellular kinase domain to the nucleus is required for the XA21-mediated immune response. These results suggest a new model for immune receptor function: on receptor recognition of conserved microbial signatures, the associated kinase translocates to the nucleus where it directly interacts with transcriptional regulators. The rice pattern recognition receptor—XA21—confers immunity against the Gram-negative bacterial pathogen, Xanthomonas oryzae pv. oryzae . This study shows that the intracellular kinase domain of XA21 translocates to the nucleus and that this translocation is essential for the XA21-mediated immune response.