zum Inhalt springen
Jia, A., Huang, S,. Song, W., Wang, J., Meng, Y,. Sun, Y., Xu, L., Laessle, H., Jirschitzka, J., Hou, J., Zhang, T., Yu, W., Hessler, G., Li, E., Ma, S., Yu, D., Gebauer, J., Baumann, U., Liu, X., Han, Z., Chang, J., Parker, J.E., Chai, J.

TIR-catalyzed ADP-ribosylation reactions produce signaling molecules for plant immunity

Abstract

Plant pathogen-activated immune signaling by nucleotide-binding leucine-rich repeat (NLR) receptors with an N-terminal Toll/Interleukin-1 receptor (TIR) domain converges on Enhanced Disease Susceptibility 1 (EDS1) and its direct partners Phytoalexin Deficient 4 (PAD4) or Senescence-Associated Gene 101 (SAG101). TIR-encoded NADases produce signaling molecules to promote exclusive EDS1-PAD4 and EDS1-SAG101 interactions with helper NLR sub-classes. Here we show that TIR-containing proteins catalyze adenosine diphosphate (ADP)-ribosylation of adenosine triphosphate (ATP) and ADP ribose (ADPR) via ADPR polymerase-like and NADase activity, forming ADP-ribosylated ATP (ADPr-ATP) and ADPr-ADPR (di-ADPR), respectively. Specific binding of ADPr-ATP or di-ADPR allosterically promotes EDS1-SAG101 interaction with helper NLR N requirement gene 1A (NRG1A) in vitro and in planta. Our data reveal an enzymatic activity of TIRs that enables specific activation of the EDS1-SAG101-NRG1 immunity branch.

 Read more at Science10.1126/science.abq8180