title: Promotion of sporulation by caffeine pretreatment in Saccharomyces cerevisiae. II. Changes in ribonuclease activity during sporulation.
abstract: Changes in RNase activity during sporulation of a homothallic diploid strain of Saccharomyces cerevisiae were measured in caffeine-treated and non-treated cells. 1. In caffeine-treated cells soon after the transfer to the sporulation medium a significant increase in RNase activity was observed; in control cells the rise of RNase activity was less and started after a lag period of 5 h. The final activity of RNase activity was about twice as high in caffeine-treated cells as in control cells. 2. Increase in RNase activity during sporulation was sensitive to cycloheximide in control cells, but insensitive in caffeine-treated cells. 3. RNases from vegetative cells and from sporulating ones are different in their Km values. Relation of the changes in RNase activity to premeiotic DNA synthesis is discussed.
mesh_terms: D002110:Caffeine / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D007700:Kinetics; D012260:Ribonucleases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D013172:Spores, Fungal / Q000254:growth & development
chemical_list: D002110:Caffeine; D004247:DNA; D003513:Cycloheximide; D012260:Ribonucleases