title: Signaling molecules: hydrogen sulfide and polysulfide.
abstract: CONCLUSIONS
  Hydrogen sulfide (H2S) has been recognized as a signaling molecule as well as a cytoprotectant. It modulates neurotransmission, regulates vascular tone, and protects various tissues and organs, including neurons, the heart, and kidneys, from oxidative stress and ischemia-reperfusion injury. H2S is produced from l-cysteine by cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3MST) along with cysteine aminotransferase.
  
  
  BACKGROUND
  In addition to these enzymes, we recently identified a novel pathway to produce H2S from d-cysteine, which involves d-amino acid oxidase (DAO) along with 3MST. These enzymes are localized in the cytoplasm, mitochondria, and peroxisomes. However, some enzymes translocate to organelles under specific conditions. Moreover, H2S-derived potential signaling molecules such as polysulfides and HSNO have been identified.
  
  
  RESULTS
  The physiological stimulations, which trigger the production of H2S and its derivatives and maintain their local levels, remain unclear.
  
  
  CONCLUSIONS
  Understanding the regulation of the H2S production and H2S-derived signaling molecules and the specific stimuli that induce their release will provide new insights into the biology of H2S and therapeutic development in diseases involving these substances.
authors.affiliation: National Institute of Neuroscience , National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan .
authors.forename: Hideo
authors.initials: H
authors.lastname: Kimura
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D003541:Cystathionine beta-Synthase / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D003605:D-Amino-Acid Oxidase / Q000378:metabolism; D064426:Gasotransmitters / Q000378:metabolism*; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D020675:Peroxisomes / Q000378:metabolism; D015398:Signal Transduction; D013440:Sulfides / Q000378:metabolism*; D013466:Sulfurtransferases / Q000378:metabolism
chemical_list: D064426:Gasotransmitters; D013440:Sulfides; C032915:polysulfide; D003605:D-Amino-Acid Oxidase; D013466:Sulfurtransferases; C021550:3-mercaptopyruvate sulphurtransferase; D003541:Cystathionine beta-Synthase; D003545:Cysteine; D002118:Calcium; D006862:Hydrogen Sulfide