Elucidating RIN4-Mediated Immune Signaling Cascades in Arabidopsis

Summary

Principal Investigator: GITTA LAUREL COAKER
Affiliation: University of California
Country: USA
Abstract: DESCRIPTION (provided by applicant): Multiple key components of the innate immune system are conserved across eukaryotes. In plants, the innate immune system serves as a barrier to inhibit both pathogen entry and multiplication. Despite the importance of the innate immune system, scientists still have a limited understanding of how plant immune complexes are assembled and regulated in response to pathogen perception. A key regulator of the plant immune system is the Arabidopsis gene RIN4. RIN4 is conserved among all land plants and acts to regulate immune perception of the bacterial pathogen Pseudomonas syringae pv. tomato in Arabidopsis. Preliminary data within this application demonstrate the purification of RIN4 protein complexes in the absence and presence of pathogen stimulus. Fifteen novel proteins were identified by mass spectrometry and multiple proteins were subsequently shown to interact with RIN4 by yeast two-hybrid. Arabidopsis knockout or overexpression lines for three of these RIN4 associated proteins display altered defense responses to P. syringae pv. tomato, suggesting that they are important components of the plant immune response. One RIN4 associated protein is the H+ATPase AHA1. Experiments indicate that RIN4 can directly regulate AHA1 enzymatic activity. RIN4 can work in concert with AHA1 to regulate leaf stomatal opening during the innate immune responses, thus blocking the entry of bacterial pathogens into the leaf interior. The central hypothesis of the proposed research is that RIN4 complex constituents will be key components controlling innate immune signaling. Several proposed experiments seek to understand RIN4 protein complex assembly and RIN4-mediated cellular signaling cascades using the P. syringae-Arabidopsis pathosystem. This pathosystem is an excellent model system to study eukaryotic innate immune signaling because of the extensive genetic resources available, the fast generation time of Arabidopsis, and the similarities between innate immune systems in plants and other eukaryotes. The specific aims of this research application are the following: 1) Elucidate the mechanism RIN4 uses to regulate plasma membrane H+ATPase activity;2) Investigate the spatial and temporal components of the RIN4 protein network;3) Functionally characterize Arabidopsis RIN4 associated proteins. PUBLIC HEALTH RELEVANCE: RIN4 is a central player in the regulation and activation of membrane-localized plant innate immune protein complexes. Multiple RIN4 associated proteins are widely conserved among eukaryotes and several have been implicated in immune signaling in mammals. Because there are significant similarities between innate immune systems in plants and other eukaryotes, we anticipate our findings will be broadly relevant to NIH's mission.
Funding Period: ----------------2010 - ---------------2015-
more information: NIH RePORT

Top Publications

  1. pmc The Pseudomonas syringae type III effector AvrRpt2 promotes pathogen virulence via stimulating Arabidopsis auxin/indole acetic acid protein turnover
    Fuhao Cui
    Department of Plant Pathology, China Agricultural University, Beijing 100193, China
    Plant Physiol 162:1018-29. 2013
  2. pmc Cyclophilin 20-3 relays a 12-oxo-phytodienoic acid signal during stress responsive regulation of cellular redox homeostasis
    Sang Wook Park
    Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
    Proc Natl Acad Sci U S A 110:9559-64. 2013
  3. pmc Recognition of bacterial plant pathogens: local, systemic and transgenerational immunity
    Elizabeth Henry
    Department of Plant Pathology, University of California at Davis, Davis, CA, USA
    New Phytol 199:908-15. 2013
  4. pmc The role of the plasma membrane H+-ATPase in plant-microbe interactions
    James Mitch Elmore
    Department of Plant Pathology, University of California, Davis, CA 95616, USA
    Mol Plant 4:416-27. 2011
  5. pmc A receptor-like cytoplasmic kinase phosphorylates the host target RIN4, leading to the activation of a plant innate immune receptor
    Jun Liu
    Department of Plant Pathology, University of California, Davis, 95616, USA
    Cell Host Microbe 9:137-46. 2011
  6. pmc Plant NB-LRR signaling: upstreams and downstreams
    James Mitch Elmore
    Department of Plant Pathology, University of California, Davis, CA 95616, United States
    Curr Opin Plant Biol 14:365-71. 2011
  7. pmc Quantitative proteomics reveals dynamic changes in the plasma membrane during Arabidopsis immune signaling
    James Mitch Elmore
    University of California at Davis, Davis, California 95616, USA
    Mol Cell Proteomics 11:M111.014555. 2012

Detail Information

Publications8

  1. pmc The Pseudomonas syringae type III effector AvrRpt2 promotes pathogen virulence via stimulating Arabidopsis auxin/indole acetic acid protein turnover
    Fuhao Cui
    Department of Plant Pathology, China Agricultural University, Beijing 100193, China
    Plant Physiol 162:1018-29. 2013
    ..Thus, promoting auxin response via modulating the stability of the key transcription repressors Aux/IAA is a mechanism used by the bacterial type III effector AvrRpt2 to promote pathogenicity...
  2. pmc Cyclophilin 20-3 relays a 12-oxo-phytodienoic acid signal during stress responsive regulation of cellular redox homeostasis
    Sang Wook Park
    Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
    Proc Natl Acad Sci U S A 110:9559-64. 2013
    ..Thus, we conclude that CYP20-3 is a key effector protein that links OPDA signaling to amino acid biosynthesis and cellular redox homeostasis in stress responses...
  3. pmc Recognition of bacterial plant pathogens: local, systemic and transgenerational immunity
    Elizabeth Henry
    Department of Plant Pathology, University of California at Davis, Davis, CA, USA
    New Phytol 199:908-15. 2013
    ..Taken together, these recent advances bring us closer to understanding the web of molecular interactions responsible for coordinating defense responses and ultimately resistance. ..
  4. pmc The role of the plasma membrane H+-ATPase in plant-microbe interactions
    James Mitch Elmore
    Department of Plant Pathology, University of California, Davis, CA 95616, USA
    Mol Plant 4:416-27. 2011
    ..Thus, these ubiquitous plant enzymes contribute to plant immune responses and are targeted by pathogens to increase plant susceptibility...
  5. pmc A receptor-like cytoplasmic kinase phosphorylates the host target RIN4, leading to the activation of a plant innate immune receptor
    Jun Liu
    Department of Plant Pathology, University of California, Davis, 95616, USA
    Cell Host Microbe 9:137-46. 2011
    ..Taken together, our results demonstrate that the RIPK kinase associates with and modifies an effector-targeted protein complex to initiate host immunity...
  6. pmc Plant NB-LRR signaling: upstreams and downstreams
    James Mitch Elmore
    Department of Plant Pathology, University of California, Davis, CA 95616, United States
    Curr Opin Plant Biol 14:365-71. 2011
    ..In this review we highlight recent advances in understanding NB-LRR function...
  7. pmc Quantitative proteomics reveals dynamic changes in the plasma membrane during Arabidopsis immune signaling
    James Mitch Elmore
    University of California at Davis, Davis, California 95616, USA
    Mol Cell Proteomics 11:M111.014555. 2012
    ..This study presents the largest quantitative proteomics data set of plant immunity to date and provides a framework for understanding global plasma membrane proteome dynamics during plant immune responses...