Changes in the glutathione thiol-disulfide status of Neurospora crassa conidia during germination and aging.
Improved methods were developed for the determination of reduced glutathione (GSH), glutathione disulfide (GSSG), and protein-glutathione disulfide (PSSG) and applied to determine the glutathione status at various stages of the asexual life cycle for the band strain of Neurospora crassa. The GSH-GSSG ratio in freshly harvested dry conidia was found to be about 150 but decreased to around 6 when dryconidia were aged (stored) for 10 days after harvest. When conidia were germinated, this ratio increased to about 300 during the first 10 min of the 6-h germination process. In mycelia, during log-phase growth, the ratio was about 10-3. Changes in the ratio occurred primarily through changes in the GSSG content, which ranges from about 0.023 (mycelia) to 2(10-day aged conidia) mumol per g (dry weight) of residue, whereas GSH levels varied by a factor of about two. The PSSG content varied from 0.02 (mycelia) to 0.6 (10-day aged conidia) mumol per g (dry weight) of residue and generally paralleled the GSSG content. The results demonstrate the potential importance of thiol-disulfide reactions as a mechanism for the control of physiological properties associated with dormancy, and the observed changes in GSSG level are found to be compatible with the view that GSSG plays a role in the regulation of protein synthesis through control of polysome formation.
D002474:Cell-Free System; D004220:Disulfides / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism; D009491:Neurospora / Q000378:metabolism*; D009492:Neurospora crassa / Q000254:growth & development / Q000378:metabolism*; D011485:Protein Binding; D013056:Spectrophotometry, Ultraviolet; D013172:Spores, Fungal / Q000254:growth & development / Q000378:metabolism; D013997:Time Factors
D004220:Disulfides; D005656:Fungal Proteins; D005980:Glutathione Reductase; D005978:Glutathione