title: Identification of potential protein dithiol-disulfide substrates of mammalian Grx2.
abstract: BACKGROUND
  Glutaredoxins (Grxs) catalyze the reduction of protein disulfides via the dithiol mechanism and the de-/glutathionylation of substrates via the monothiol mechanism. These rapid, specific, and generally also reversible modifications are part of various signaling cascades regulating for instance cell proliferation, differentiation and apoptosis. Even though crucial functions of the conserved, mitochondrial Grx2a and the cytosolic/nuclear Grx2c isoforms have been proposed, only a few substrates have been identified in vitro or in vivo. The significance of redox signaling is emerging, yet a general lack of methods for the time-resolved analysis of these distinct and rapid modifications in vivo constitutes the biggest challenge in the redox signaling field.
  
  
  RESULTS
  Here, we have identified potential interaction partners for Grx2 isoforms in human HeLa cells and mouse tissues by an intermediate trapping approach. Some of the 50 potential substrates are part of the cytoskeleton or act in protein folding, cellular signaling and metabolism. Part of these interactions were further verified by immunoprecipitation or a newly established 2-D redox blot.
  
  
  CONCLUSIONS
  Our study demonstrates that Grx2 catalyzes both the specific oxidation and the reduction of cysteinyl residues in the same compartment at the same time and without affecting the global cellular thiol-redox state.
  
  
  CONCLUSIONS
  The knowledge of specific targets will be helpful in understanding the functions of Grx2. The 2-D redox blot may be useful for the analysis of the overall thiol-redox state of proteins with high molecular weight and numerous cysteinyl residues, that evaded analysis by previously described methods.
authors.affiliation: Institute for Clinical Cytobiology and Cytopathology, Philipps-University Marburg, Germany.
authors.forename: Lena Dorothee
authors.initials: LD
authors.lastname: Schütte
authors.forename: Stefan
authors.initials: S
authors.lastname: Baumeister
authors.forename: Benjamin
authors.initials: B
authors.lastname: Weis
authors.forename: Christoph
authors.initials: C
authors.lastname: Hudemann
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Hanschmann
authors.forename: Christopher Horst
authors.initials: CH
authors.lastname: Lillig
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004220:Disulfides / Q000378:metabolism*; D054477:Glutaredoxins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008322:Mammals / Q000378:metabolism; D051379:Mice; D010084:Oxidation-Reduction; D017510:Protein Folding; D054730:Protein Interaction Domains and Motifs; D020033:Protein Isoforms; D011506:Proteins / Q000378:metabolism*; D014050:Toluene / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D004220:Disulfides; D054477:Glutaredoxins; D020033:Protein Isoforms; D011506:Proteins; D014050:Toluene; C004848:dithiol
keywords: Glutaredoxin; Intermediate trapping; Protein disulfide; Proteomics; Redox blot; Redox state