title: The E3 ligase OsPUB15 interacts with the receptor-like kinase PID2 and regulates plant cell death and innate immunity.
abstract: BACKGROUND
  Rice blast disease is one of the most destructive diseases of rice worldwide. We previously cloned the rice blast resistance gene Pid2, which encodes a transmembrane receptor-like kinase containing an extracellular B-lectin domain and an intracellular serine/threonine kinase domain. However, little is known about Pid2-mediated signaling.
  
  
  RESULTS
  Here we report the functional characterization of the U-box/ARM repeat protein OsPUB15 as one of the PID2-binding proteins. We found that OsPUB15 physically interacted with the kinase domain of PID2 (PID2K) in vitro and in vivo and the ARM repeat domain of OsPUB15 was essential for the interaction. In vitro biochemical assays indicated that PID2K possessed kinase activity and was able to phosphorylate OsPUB15. We also found that the phosphorylated form of OsPUB15 possessed E3 ligase activity. Expression pattern analyses revealed that OsPUB15 was constitutively expressed and its encoded protein OsPUB15 was localized in cytosol. Transgenic rice plants over-expressing OsPUB15 at early stage displayed cell death lesions spontaneously in association with a constitutive activation of plant basal defense responses, including excessive accumulation of hydrogen peroxide, up-regulated expression of pathogenesis-related genes and enhanced resistance to blast strains. We also observed that, along with plant growth, the cell death lesions kept spreading over the whole seedlings quickly resulting in a seedling lethal phenotype.
  
  
  CONCLUSIONS
  These results reveal that the E3 ligase OsPUB15 interacts directly with the receptor-like kinase PID2 and regulates plant cell death and blast disease resistance.
authors: Jing
authors: J
authors: Wang
authors: Baoyuan
authors: B
authors: Qu
authors: Shijuan
authors: S
authors: Dou
authors: Liyun
authors: L
authors: Li
authors: Dedong
authors: D
authors: Yin
authors: Zhiqian
authors: Z
authors: Pang
authors: Zhuangzhi
authors: Z
authors: Zhou
authors: Miaomiao
authors: M
authors: Tian
authors: Guozhen
authors: G
authors: Liu
authors: Qi
authors: Q
authors: Xie
authors: Dingzhong
authors: D
authors: Tang
authors: Xuewei
authors: X
authors: Chen
authors: Lihuang
authors: L
authors: Zhu
mesh_terms: D000595:Amino Acid Sequence; D016923:Cell Death; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate; D020082:Magnaporthe / Q000502:physiology; D012275:Oryza / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity / Q000502:physiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000276:immunology / Q000502:physiology; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D044767:Ubiquitin-Protein Ligases; D011494:Protein Kinases