title: The LSD1-interacting protein GILP is a LITAF domain protein that negatively regulates hypersensitive cell death in Arabidopsis.
abstract: BACKGROUND
  Hypersensitive cell death, a form of avirulent pathogen-induced programmed cell death (PCD), is one of the most efficient plant innate immunity. However, its regulatory mechanism is poorly understood. AtLSD1 is an important negative regulator of PCD and only two proteins, AtbZIP10 and AtMC1, have been reported to interact with AtLSD1.
  
  
  RESULTS
  To identify a novel regulator of hypersensitive cell death, we investigate the possible role of plant LITAF domain protein GILP in hypersensitive cell death. Subcellular localization analysis showed that AtGILP is localized in the plasma membrane and its plasma membrane localization is dependent on its LITAF domain. Yeast two-hybrid and pull-down assays demonstrated that AtGILP interacts with AtLSD1. Pull-down assays showed that both the N-terminal and the C-terminal domains of AtGILP are sufficient for interactions with AtLSD1 and that the N-terminal domain of AtLSD1 is involved in the interaction with AtGILP. Real-time PCR analysis showed that AtGILP expression is up-regulated by the avirulent pathogen Pseudomonas syringae pv. tomato DC3000 avrRpt2 (Pst avrRpt2) and fumonisin B1 (FB1) that trigger PCD. Compared with wild-type plants, transgenic plants overexpressing AtGILP exhibited significantly less cell death when inoculated with Pst avrRpt2, indicating that AtGILP negatively regulates hypersensitive cell death.
  
  
  CONCLUSIONS
  These results suggest that the LITAF domain protein AtGILP localizes in the plasma membrane, interacts with AtLSD1, and is involved in negatively regulating PCD. We propose that AtGILP functions as a membrane anchor, bringing other regulators of PCD, such as AtLSD1, to the plasma membrane. Human LITAF domain protein may be involved in the regulation of PCD, suggesting the evolutionarily conserved function of LITAF domain proteins in the regulation of PCD.
authors.affiliation: The State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China.
authors.forename: Shanping
authors.initials: S
authors.lastname: He
authors.forename: Guihong
authors.initials: G
authors.lastname: Tan
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Kuowei
authors.initials: K
authors.lastname: Huang
authors.forename: Jiao
authors.initials: J
authors.lastname: Ren
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiangchun
authors.initials: X
authors.lastname: Yu
authors.forename: Ping
authors.initials: P
authors.lastname: Huang
authors.forename: Chengcai
authors.initials: C
authors.lastname: An
mesh_terms: D000595:Amino Acid Sequence; D051017:Apoptosis Regulatory Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D016923:Cell Death / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D037341:Fumonisins / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000187:drug effects; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000187:drug effects; D044224:Pseudomonas syringae / Q000187:drug effects; D014157:Transcription Factors / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D051017:Apoptosis Regulatory Proteins; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D037341:Fumonisins; C560258:GILP protein, Arabidopsis; C104920:LSD1 protein, Arabidopsis; C089426:RPS2 protein, Arabidopsis; D014157:Transcription Factors; C056933:fumonisin B1