Uncoiling CNLs: Structure/Function Approaches to Understanding CC Domain Function in Plant NLRs

@article{Bentham2018UncoilingCS,
  title={Uncoiling CNLs: Structure/Function Approaches to Understanding CC Domain Function in Plant NLRs},
  author={Adam R. Bentham and Rafał Zdrzałek and Juan Carlos De la Concepcion and Mark J. Banfield},
  journal={Plant and Cell Physiology},
  year={2018},
  volume={59},
  pages={2398 - 2408}
}
Abstract Plant nucleotide-binding leucine-rich repeat receptors (NLRs) are intracellular pathogen receptors whose N-terminal domains are integral to signal transduction after perception of a pathogen-derived effector protein. The two major plant NLR classes are defined by the presence of either a Toll/interleukin-1 receptor (TIR) or a coiled-coil (CC) domain at their N-terminus (TNLs and CNLs). Our knowledge of how CC domains function in plant CNLs lags behind that of how TIR domains function… 

Figures from this paper

Genome-wide functional analyses of plant coiled–coil NLR-type pathogen receptors reveal essential roles of their N-terminal domain in oligomerization, networking, and immunity
TLDR
It is shown that upon pathogen perception, NLRs use their N-terminal domains to transactivate other receptors, suggesting that plant NLRs oligomerize upon activation, similar to the vertebrate NLRs; however, consistent with their large number in plants, the complexes are highly heterometric.
Advancement of research on plant NLRs evolution, biochemical activity, structural association, and engineering.
TLDR
A review of evolution of plant intracellular immune receptors, oligomeric complex formation, enzymatic action, engineering, and mechanisms of immune inspection for appropriate defense outcomes highlights structural basis of perception of the virulence factors by NLRs or NLR pairs to design novel classes of plant immune receptors.
Diversity, structure and function of the coiled-coil domains of plant NLR immune receptors.
TLDR
This review outlines the current understanding of NLR CC domains, including their diversity/classification and structure, their roles in cell death induction, disease resistance, and interaction with other proteins, and provides possible directions for future work.
RPW8/HR repeats control NLR activation in Arabidopsis thaliana
TLDR
Deleterious allele-specific interactions between an NLR and a non-NLR gene cluster are reported, resulting in not one, but multiple hybrid necrosis cases in Arabidopsis thaliana.
An N-terminal motif in NLR immune receptors is functionally conserved across distantly related plant species
TLDR
In vitro Mu transposition is used to generate a random truncation library and identify the minimal functional region of NLRs and revealed that the NRC4 N-terminal 29 amino acids are sufficient to induce hypersensitive cell death.
Three conserved hydrophobic residues in the CC domain of Pit contribute to its plasma membrane localization and immune induction
TLDR
It is revealed that the rice NLR Pit self-associates through its CC domain, and the role of the three conserved hydrophobic residues in Pit is found to be involved in the plasma membrane localization.
Help wanted: helper NLRs and plant immune responses.
Plant pathogens convergently evolved to counteract redundant nodes of an NLR immune receptor network
TLDR
Plant pathogens have evolved to counteract central nodes of the NRC immune receptor network through different mechanisms, concluding that NRC diversification into functionally redundant nodes in a massively expanded NLR network.
...
...

References

SHOWING 1-10 OF 89 REFERENCES
A novel conserved mechanism for plant NLR protein pairs: the “integrated decoy” hypothesis
TLDR
An “integrated decoy” model for the function of these receptor complexes is described, in which a plant protein targeted by an effector has been duplicated and fused to one member of the NLR pair, where it acts as a bait to trigger defense signaling by the second NLR upon effector binding.
Animal NLRs provide structural insights into plant NLR function
TLDR
The similarities and differences between plant and animal NLRs are assessed, and the structural information on the animal NLR pair NAIP/NLRC4 is used to derive a plausible model for plant NLR activation.
Structure-Function Analysis of Barley NLR Immune Receptor MLA10 Reveals Its Cell Compartment Specific Activity in Cell Death and Disease Resistance
TLDR
Data showing an essential and sufficient nuclear MLA10 activity in disease resistance and cell death signaling in barley and Nicotiana benthamiana suggests a bifurcation of MLA10-triggered cell death and disease resistance signaling in a compartment-dependent manner.
Integration of decoy domains derived from protein targets of pathogen effectors into plant immune receptors is widespread
TLDR
This study suggests that integration of decoy domains in NLR immune receptors is widespread and frequent in plants and the integrated decoy model is therefore a powerful concept to identify new proteins involved in disease resistance.
The “sensor domains” of plant NLR proteins: more than decoys?
TLDR
It is proposed to refer to the extraneous domains of classic NLR proteins described by Cesari et al. (2014) as sensor domains (SD), a term that is agnostic to any potential biochemical activities of the integrated module.
Structural basis of pathogen recognition by an integrated HMA domain in a plant NLR immune receptor
TLDR
The structural basis for direct recognition of AVR-Pik, an effector from the rice blast pathogen, by the rice intracellular NLR immune receptor Pik is described.
Pathogen perception by NLRs in plants and animals: Parallel worlds
TLDR
By assessing commonalities and differences between kingdoms, this work is able to develop a more complete understanding of NLR function and provide novel insights into signalling‐competent NLRs.
Comparative analysis of plant immune receptor architectures uncovers host proteins likely targeted by pathogens
TLDR
It is hypothesized that NLR-IDs that are revealed provide clues to the host proteins targeted by pathogens, and that this information can be deployed to discover new sources of disease resistance.
The Coiled-Coil and Nucleotide Binding Domains of the Potato Rx Disease Resistance Protein Function in Pathogen Recognition and Signaling[W][OA]
TLDR
A model of CC-NB-LRR function wherein the LRR and CC domains coregulate the signaling activity of the NB domain in a recognition-specific manner is described.
...
...