title: Hydrogen sulfide is produced by cystathionine γ-lyase at the steady-state low intracellular Ca(2+) concentrations.
abstract: Hydrogen sulfide (H(2)S) is recognized as a physiologic mediator produced in a variety of tissues. It is produced by three enzymes, cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3MST). However, the regulation of H(2)S production by CSE has not well been understood. Here we show that H(2)S producing activity of CSE is regulated by intracellular Ca(2+) concentrations. In the presence of pyridoxal 5'-phosphate (PLP) CSE efficiently produces H(2)S at the steady-state low Ca(2+) concentrations but is suppressed at high Ca(2+) concentrations. In the absence of PLP H(2)S production maintains the suppressed levels at high Ca(2+) concentrations and decreased further at low Ca(2+) concentrations. These observations suggest that CSE produces H(2)S at the steady-state in cells and that the production is suppressed when the intracellular Ca(2+) concentrations are increased.
authors: Department of Molecular Pharmacology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan.
authors: Yoshinori
authors: Y
authors: Mikami
authors: Norihiro
authors: N
authors: Shibuya
authors: Yuki
authors: Y
authors: Ogasawara
authors: Hideo
authors: H
authors: Kimura
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D003542:Cystathionine gamma-Lyase / Q000737:chemistry / Q000378:metabolism*; D006862:Hydrogen Sulfide / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D011732:Pyridoxal Phosphate / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar
chemical_list: D011732:Pyridoxal Phosphate; D003542:Cystathionine gamma-Lyase; D002118:Calcium; D006862:Hydrogen Sulfide