Dataset Information

Distinct modes of derepression of an Arabidopsis immune receptor complex by two different bacterial effectors.

ABSTRACT: Plant intracellular nucleotide-binding leucine-rich repeat (NLR) immune receptors often function in pairs to detect pathogen effectors and activate defense. The Arabidopsis RRS1-R-RPS4 NLR pair recognizes the bacterial effectors AvrRps4 and PopP2 via an integrated WRKY transcription factor domain in RRS1-R that mimics the effector's authentic targets. How the complex activates defense upon effector recognition is unknown. Deletion of the WRKY domain results in an RRS1 allele that triggers constitutive RPS4-dependent defense activation, suggesting that in the absence of effector, the WRKY domain contributes to maintaining the complex in an inactive state. We show the WRKY domain interacts with the adjacent domain 4, and that the inactive state of RRS1 is maintained by WRKY-domain 4 interactions before ligand detection. AvrRps4 interaction with the WRKY domain disrupts WRKY-domain 4 association, thus derepressing the complex. PopP2-triggered activation is less easily explained by such disruption and involves the longer C-terminal extension of RRS1-R. Furthermore, some mutations in RPS4 and RRS1 compromise PopP2 but not AvrRps4 recognition, suggesting that AvrRps4 and PopP2 derepress the complex differently. Consistent with this, a "reversibly closed" conformation of RRS1-R, engineered in a method exploiting the high affinity of colicin E9 and Im9 domains, reversibly loses AvrRps4, but not PopP2 responsiveness. Following RRS1 derepression, interactions between domain 4 and the RPS4 C-terminal domain likely contribute to activation. Simultaneous relief of autoinhibition and activation may contribute to defense activation in many immune receptors.

SUBMITTER: Ma Y

PROVIDER: S-EPMC6187137 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Distinct modes of derepression of an <i>Arabidopsis</i> immune receptor complex by two different bacterial effectors.

Ma Yan Y Guo Hailong H Hu Lanxi L Martinez Paula Pons PP Moschou Panagiotis N PN Cevik Volkan V Ding Pingtao P Duxbury Zane Z Sarris Panagiotis F PF Jones Jonathan D G JDG

Proceedings of the National Academy of Sciences of the United States of America 20180925 41

Plant intracellular nucleotide-binding leucine-rich repeat (NLR) immune receptors often function in pairs to detect pathogen effectors and activate defense. The <i>Arabidopsis</i> RRS1-R-RPS4 NLR pair recognizes the bacterial effectors AvrRps4 and PopP2 via an integrated WRKY transcription factor domain in RRS1-R that mimics the effector's authentic targets. How the complex activates defense upon effector recognition is unknown. Deletion of the WRKY domain results in an RRS1 allele that triggers ...[more]

PMID: 30254172

Similar Datasets

Project description:UnlabelledNADH:quinone oxidoreductase (complex I) is a bioenergetic enzyme that transfers electrons from NADH to quinone, conserving the energy of this reaction by contributing to the proton motive force. While the importance of NADH oxidation to mitochondrial aerobic respiration is well documented, the contribution of complex I to bacterial electron transport chains has been tested in only a few species. Here, we analyze the function of two phylogenetically distinct complex I isozymes in Rhodobacter sphaeroides, an alphaproteobacterium that contains well-characterized electron transport chains. We found that R. sphaeroides complex I activity is important for aerobic respiration and required for anaerobic dimethyl sulfoxide (DMSO) respiration (in the absence of light), photoautotrophic growth, and photoheterotrophic growth (in the absence of an external electron acceptor). Our data also provide insight into the functions of the phylogenetically distinct R. sphaeroidescomplex I enzymes (complex IA and complex IE) in maintaining a cellular redox state during photoheterotrophic growth. We propose that the function of each isozyme during photoheterotrophic growth is either NADH synthesis (complex IA) or NADH oxidation (complex IE). The canonical alphaproteobacterial complex I isozyme (complex IA) was also shown to be important for routing electrons to nitrogenase-mediated H2 production, while the horizontally acquired enzyme (complex IE) was dispensable in this process. Unlike the singular role of complex I in mitochondria, we predict that the phylogenetically distinct complex I enzymes found across bacterial species have evolved to enhance the functions of their respective electron transport chains.ImportanceCells use a proton motive force (PMF), NADH, and ATP to support numerous processes. In mitochondria, complex I uses NADH oxidation to generate a PMF, which can drive ATP synthesis. This study analyzed the function of complex I in bacteria, which contain more-diverse and more-flexible electron transport chains than mitochondria. We tested complex I function in Rhodobacter sphaeroides, a bacterium predicted to encode two phylogenetically distinct complex I isozymes. R. sphaeroides cells lacking both isozymes had growth defects during all tested modes of growth, illustrating the important function of this enzyme under diverse conditions. We conclude that the two isozymes are not functionally redundant and predict that phylogenetically distinct complex I enzymes have evolved to support the diverse lifestyles of bacteria.

Dataset Information

Distinct modes of derepression of an Arabidopsis immune receptor complex by two different bacterial effectors.

Publications

Distinct modes of derepression of an <i>Arabidopsis</i> immune receptor complex by two different bacterial effectors.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets