Preliminary characterization of maturation-promoting factor from yeast Saccharomyces cerevisiae.
It has been known for some time that maturation-promoting factor (MPF) appears in a wide variety of eukaryotic cells at M phase and exerts equal M-phase-promoting activity in both meiotic cells and mitotic cells in a non-specific manner. MPF was extracted from cdc20 mutant cells of the yeast Saccharomyces cerevisiae synchronized at M phase by incubation at the restrictive temperature. When injected into immature oocytes of Xenopus laevis, yeast MPF caused meiosis reinitiation in a dose-dependent manner and even in the presence of cycloheximide. Yeast MPF exerted its activity in starfish oocytes as well. MPF activity was obtained only from cells in M phase and not from G1, S or G2 phase cells, indicating cyclical changes during the yeast mitotic cell cycle. Preliminary characterization of yeast MPF revealed that its activity was associated with a heat-labile protein having a sedimentation coefficient value of 6 S. In contrast to the current assumption that MPF is a Ca-sensitive phosphoprotein stabilized by phosphorylated small molecules, such as ATP and Na-beta-glycerophosphate, the present study revealed that yeast MPF was still active even after treatment with either Ca2+ or alkaline phosphatase. Furthermore, it was found that yeast MPF and these phosphorylated small molecules were complementary in inducing reinitiation of meiosis, since the meiosis-reinitiating activity was detected only when both were present simultaneously and almost undetectable when either of them was present alone.(ABSTRACT TRUNCATED AT 250 WORDS)
Tachibana
K
K
Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan.
Yanagishima
N
N
Kishimoto
T
T
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000469:Alkaline Phosphatase / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D005994:Glycerophosphates / Q000494:pharmacology; D006133:Growth Substances / Q000302:isolation & purification* / Q000494:pharmacology; D016200:Maturation-Promoting Factor; D008938:Mitosis / Q000187:drug effects; D009865:Oocytes / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013215:Starfish; D014982:Xenopus laevis
D005994:Glycerophosphates; D006133:Growth Substances; D000255:Adenosine Triphosphate; D016200:Maturation-Promoting Factor; D000469:Alkaline Phosphatase; D002118:Calcium; C031463:beta-glycerophosphoric acid