microbiology, Vol 141, 2463-2469, Copyright © 1995 by Society for General Microbiology
Analysis of lysine-dependent yeast sporulation: a decrease in cyclic AMP is not required for initiation of meiosis and sporulation in Saccharomyces cerevisiae
T Suizu, H Tsutsumi, A Kawado, T Inose, K Suginami and K Murata
Research Institute, Gekkeikan Sake, Co., Ltd, Kyoto, Japan.
Cells of the yeast Saccharomyces cerevisiae sporulated in nutrient-rich
medium containing L-lysine. Sporulation was specific to the presence of
L-lysine and was initiated when the cellular content of this basic amino
acid reached approximately 0.2-0.5 mmol (g cells)-1, at early stationary
phase. The formation of asci was most efficient at pH 7.0 and 50-100 mM
L-lysine; in these optimum conditions, the sporulation frequency reached
about 60% after 5 d incubation. The L-lysine- dependent sporulation system
in nutrient-rich conditions was distinct from the currently used
potassium-acetate-dependent system in nutrient- deficient conditions.
Analysis of the L-lysine-dependent system indicated that, prior to entrance
into meiosis and/or sporulation processes, the yeast cells change in shape,
their pool sizes for L- cysteine and glutathione alter, and they synthesize
a protein with a molecular mass of 15 kDa. A low level of cAMP was not
required for the entrance into meiosis and/or sporulation.
