Li M.,Peking University |
Li M.,CAS Institute of Genetics and Developmental Biology |
Ma X.,Center for Plant Biology |
Chiang Y.-H.,University of California at Davis |
And 12 more authors.
Cell Host and Microbe | Year: 2014
The cyclophilin ROC1 negatively regulates immunity specified by the NLRs RPM1 and RPS2The ROC1 prolyl-peptidyl isomerase activity is required for immune response regulationROC1 catalyzes cis/trans isomerization of the RPM1-interacting protein RIN4 at Pro149Conformation surrounding RIN4 Pro149 is a molecular switch for RPM1 activation © 2014 Elsevier Inc.
PubMed | CAS Institute of Genetics and Developmental Biology, Center for Plant Biology, Peking University and University of California at Davis
Type: Journal Article | Journal: Cell host & microbe | Year: 2014
In the absence of pathogen infection, plant effector-triggered immune (ETI) receptors are maintained in a preactivation state by intermolecular interactions with other host proteins. Pathogen effector-induced alterations activate the receptor. In Arabidopsis, the ETI receptor RPM1 is activated via bacterial effector AvrB-induced phosphorylation of the RPM1-interacting protein RIN4 at Threonine 166. We find that RIN4 also interacts with the prolyl-peptidyl isomerase (PPIase) ROC1, which is reduced upon RIN4 Thr166 phosphorylation. ROC1 suppresses RPM1 immunity in a PPIase-dependent manner. Consistent with this, RIN4 Pro149 undergoes cis/trans isomerization in the presence of ROC1. While the RIN4(P149V) mutation abolishes RPM1 resistance, the deletion of Pro149 leads to RPM1 activation in the absence of RIN4 phosphorylation. These results support a model in which RPM1 directly senses conformational changes in RIN4 surrounding Pro149 that is controlled by ROC1. RIN4 Thr166 phosphorylation indirectly regulates RPM1 resistance by modulating the ROC1-mediated RIN4 isomerization.
Wang Y.,Center for Plant Biology |
Wang Y.,Tsinghua University |
Zheng X.,Center for Plant Biology |
Zheng X.,Tsinghua University |
And 13 more authors.
Autophagy | Year: 2015
Microtubules, the major components of cytoskeleton, are involved in various fundamental biological processes in plants. Recent studies in mammalian cells have revealed the importance of microtubule cytoskeleton in autophagy. However, little is known about the roles of microtubules in plant autophagy. Here, we found that ATG6 interacts with TUB8/b-tubulin 8 and colocalizes with microtubules in Nicotiana benthamiana. Disruption of microtubules by either silencing of tubulin genes or treatment with microtubule-depolymerizing agents in N. benthamiana reduces autophagosome formation during upregulation of nocturnal or oxidation-induced macroautophagy. Furthermore, a blockage of leaf starch degradation occurred in microtubule-disrupted cells and triggered a distinct ATG6-, ATG5- and ATG7-independent autophagic pathway termed starch excess-associated chloroplast autophagy (SEX chlorophagy) for clearance of dysfunctional chloroplasts. Our findings reveal that an intact microtubule network is important for efficient macroautophagy and leaf starch degradation. © 2015, Yan Wang, Xiyin Zheng, Bingjie Yu, Shaojie Han, Jiangbo Guo, Haiping Tang, Alice Yunzi L Yu, Haiteng Deng, Yiguo Hong, and Yule Liu.
Jiang S.-C.,Center for Plant Biology |
Mei C.,Center for Plant Biology |
Wang X.-F.,Center for Plant Biology |
Zhang D.-P.,Center for Plant Biology
Plant Signaling and Behavior | Year: 2014
SOAR1 is a cytosol-nucleus dual-localized pentatricopeptide repeat (PPR) protein, which we indentified recently as a crucial regulator in the CHLH/ABAR (Mg-chelatase H subunit /putative ABA receptor)-mediated signaling pathway, acting downstream of CHLH/ABAR and upstream of a nuclear ABA-responsive bZIP transcription factor ABI5. Downregulation and upregulation of SOAR1 expression alter dramatically both ABA sensitivity and expression of a subset of key, nuclear ABA-responsive genes, suggesting that SOAR1 is a hub for ABA signaling to the nucleus, and CHLH/ABAR mediates a central signaling pathway to regulate downstream gene expression through SOAR1. © Shang-Chuan Jiang, Chao Mei, Xiao-Fang Wang, and Da-Peng Zhang.