title: Thiol-based posttranslational modifications in parasites.
abstract: CONCLUSIONS
  Cysteine residues of proteins participate in the catalysis of biochemical reactions, are crucial for redox reactions, and influence protein structure by the formation of disulfide bonds. Covalent posttranslational modifications (PTMs) of cysteine residues are important mediators of redox regulation and signaling by coupling protein activity to the cellular redox state, and moreover influence stability, function, and localization of proteins. A diverse group of protozoan and metazoan parasites are a major cause of diseases in humans, such as malaria, African trypanosomiasis, leishmaniasis, toxoplasmosis, filariasis, and schistosomiasis.
  
  
  BACKGROUND
  Human parasites undergo dramatic morphological and metabolic changes while they pass complex life cycles and adapt to changing environments in host and vector. These processes are in part regulated by PTMs of parasitic proteins. In human parasites, posttranslational cysteine modifications are involved in crucial cellular events such as signal transduction (S-glutathionylation and S-nitrosylation), redox regulation of proteins (S-glutathionylation and S-nitrosylation), protein trafficking and subcellular localization (palmitoylation and prenylation), as well as invasion into and egress from host cells (palmitoylation). This review focuses on the occurrence and mechanisms of these cysteine modifications in parasites.
  
  
  RESULTS
  Studies on cysteine modifications in human parasites are so far largely based on in vitro experiments.
  
  
  CONCLUSIONS
  The in vivo regulation of cysteine modifications and their role in parasite development will be of great interest in order to understand redox signaling in parasites.
authors.affiliation: Interdisciplinary Research Center, Justus Liebig University, Giessen, Germany.
authors.forename: Esther
authors.initials: E
authors.lastname: Jortzik
authors.forename: Lihui
authors.initials: L
authors.lastname: Wang
authors.forename: Katja
authors.initials: K
authors.lastname: Becker
mesh_terms: D000818:Animals; D003545:Cysteine / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D010084:Oxidation-Reduction; D010271:Parasites / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D015800:Protozoan Proteins / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism*
chemical_list: D015800:Protozoan Proteins; D013438:Sulfhydryl Compounds; D009569:Nitric Oxide; D005978:Glutathione; D003545:Cysteine