title: Redox sensing by proteins: oxidative modifications on cysteines and the consequent events.
abstract: CONCLUSIONS
  Reactive oxygen species (ROS) are not only essential for the cell's normal functions, but also mediate many pathological effects. When cells experience oxidative stress, proteins are modulated by redox changes and ultimately generate novel signaling patterns. It remains elusive how proteins are modulated, rather than simply damaged, by ROS and then mediate the diverse cellular responses.
  
  
  BACKGROUND
  During the past decade, researchers frequently used "redox sensor" for proteins. However, the term "redox sensing" has not been clearly defined to date. Thiols of cysteines are subjected to oxidative modifications. The conformation changes and the various types of post-translational modifications (PTMs) may result from thiol oxidation of the same protein or other proteins. The molecular effects of redox sensing include changes in protein activity, abundance, localization, and interaction with other biomacromolecules.
  
  
  RESULTS
  We discuss the emerging concept of cysteine-based redox sensing, emphasizing "sensing redox changes by proteins using their thiols." ROS are an input, and the conformation changes and/or the other PTMs after thiol oxidation are the output of redox sensing. Among dozens of redox sensing proteins listed in this article, SENP3 and caspase-9, which have been investigated in our work, are given particular attention. We also introduce the notion of biphasic and compartment-specific redox sensing by nuclear factor kappa B.
  
  
  CONCLUSIONS
  Understanding chemical modifications and conformational changes following protein redox sensing requires more studies in mass spectrometry and crystallography. Redox-indicative probes in live cells and tissues will help monitor redox-related biological and pathological progresses.
authors.affiliation: Key Laboratory of the Education Ministry for Cell Differentiation and Apoptosis, Department of Biochemistry and Molecular Cell Biology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Jing
authors.initials: J
authors.lastname: Yi
mesh_terms: D000818:Animals; D003545:Cysteine / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D010084:Oxidation-Reduction; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D011506:Proteins; D017382:Reactive Oxygen Species; D003545:Cysteine