Activation of maturation promoting factor and 26S proteasome assembly accelerated by a high concentration of 1-methyladenine in starfish oocytes.
In the oocyte maturation process of the starfish Asterina pectinifera, the extent of inhibition of germinal vesicle breakdown (GVBD) by the proteasome inhibitor MG115 (benzyloxycarbonyl-leucyl-leucyl-norvalinal), as well as the timing of activation of pre-MPF (inactive maturation promoting factor) and 26S proteasome assembly, were found to be dependent on the concentration of the maturation-inducing hormone 1-methyladenine (1-MeAde). Activation of pre-MPF was accelerated by increasing the concentration of 1-MeAde, while there was little effect on the time required for GVBD. Assembly of the 26S proteasome was also accelerated by increasing the concentration of 1-MeAde. These results indicate that a higher concentration of 1-MeAde triggers acceleration of the assembly and increase in the activity of the 26S proteasome, which results in activation of pre-MPF, although there is little effect on the timing of GVBD. It was also clarified that the timing of GVBD is controlled by a rate-liming step after MPF-activation.
Morinaga
C
C
Bioscience and Chemistry Division, Hokkaido National Industrial Research Institute, AIST, MITI, Sapporo, Japan.
Izumi
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K
Sawada
H
H
Takagi Sawada
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M
D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D016200:Maturation-Promoting Factor / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D009865:Oocytes / Q000187:drug effects* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D013215:Starfish
D009097:Multienzyme Complexes; C008407:1-methyladenine; D016200:Maturation-Promoting Factor; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D000225:Adenine