Nitric oxide as a signaling molecule in the fission yeast Schizosaccharomyces pombe.
Nitric oxide synthases (NOS) catalyze the synthesis of ubiquitous signaling molecule nitric oxide (NO) which controls numerous biological processes. Using a spectrofluorometric NOS assay, we have measured the rate of total NO production in the crude cell extracts of Schizosaccharomyces pombe. NO production was reduced in the absence of NOS cofactors calmodulin and tetrahydrobiopterin, and a competitive NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME) was able to cause a statistically significant inhibition on the rate of total NO production. These results, for the first time, provide evidence that an enzyme with a NOS-like activity may be present in the fission yeast. In order to assess the possible regulatory roles of NO as a signaling molecule in this yeast, using the differential display technique, we screened for NO-responsive genes whose expression decreased upon exposure to L-NAME and increased in response to an NO donor, sodium nitroprusside treatment. Differential expression patterns of byr1, pek1, sid1, and wis1 genes were confirmed by quantitative real-time PCR. The physiological experiments performed based on the functions and molecular interactions of these genes have pointed to the possibility that NO production might be required for sporulation in S. pombe. Taken together, these findings suggest that NO may function as a signaling molecule which can induce both transcriptional and physiological changes in the fission yeast. Hence, these data also imply that S. pombe can be used as a model system for investigating the mechanisms underlying NO-related complex signaling pathways.
Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Vezneciler, 34134 Istanbul, Turkey. cenkkig@istanbul.edu.tr
Cenk
C
Kig
Guler
G
Temizkan
D004791:Enzyme Inhibitors / Q000494:pharmacology; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects / Q000235:genetics; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012568:Schizosaccharomyces / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000502:physiology; D013172:Spores, Fungal / Q000378:metabolism / Q000502:physiology
D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D029702:Schizosaccharomyces pombe Proteins; D009599:Nitroprusside; D009569:Nitric Oxide; D019331:NG-Nitroarginine Methyl Ester