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This content will become publicly available on September 29, 2018

Title: S -Nitrosylation inhibits the kinase activity of tomato phosphoinositide-dependent kinase 1 (PDK1)

It is well known that the reactive oxygen species NO can trigger cell death in plants and other organisms, but the underlying molecular mechanisms are not well understood. Here we provide evidence that NO may trigger cell death in tomato (Solanum lycopersicum) by inhibiting the activity of phosphoinositide-dependent kinase 1 (SlPDK1), a conserved negative regulator of cell death in yeasts, mammals, and plants, via S-nitrosylation. Biotin-switch assays indicated that SlPDK1 is a target of S-nitrosylation. Moreover, the kinase activity of SlPDK1 was inhibited by S-nitrosoglutathione in a concentration-dependent manner, indicating that SlPDK1 activity is abrogated by S-nitrosylation. The S-nitrosoglutathione–induced inhibition was reversible in the presence of a reducing agent but additively enhanced by hydrogen peroxide (H 2O 2). Our LC-MS/MS analyses further indicated that SlPDK1 is primarily S-nitrosylated on a cysteine residue at position 128 (Cys 128), and substitution of Cys 128 with serine completely abolished SlPDK1 kinase activity, suggesting that S-nitrosylation of Cys 128 is responsible for SlPDK1 inhibition. In summary, our results establish a potential link between NO-triggered cell death and inhibition of the kinase activity of tomato PDK1.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [3] ;  [2]
  1. Zhejiang Normal Univ., (China)
  2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  3. Iowa State Univ., Ames, IA (United States)
Publication Date:
Report Number(s):
PNNL-SA-129673
Journal ID: ISSN 0021-9258
Grant/Contract Number:
31371401; 31571423; 0820642; 3808; AC0576RL01830
Type:
Accepted Manuscript
Journal Name:
Journal of Biological Chemistry
Additional Journal Information:
Journal Volume: 292; Journal Issue: 48; Journal ID: ISSN 0021-9258
Publisher:
American Society for Biochemistry and Molecular Biology
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES
OSTI Identifier:
1430528