Progesterone-induced changes in the phosphoryl potential during the meiotic divisions in amphibian oocytes: role of Na/K-ATPase.

ABSTRACT:

Background

Progesterone triggers resumption of the first meiotic division in the Rana pipiens oocyte by binding to the N-terminal external loop of the catalytic subunit of Na/K-ATPase, releasing a cascade of lipid second messengers. This is followed by internalization of specific membrane proteins, plasma membrane depolarization and nuclear membrane breakdown, culminating in arrest at second metaphase.

Results

Progesterone initiates an increase in phosphoryl potential during the first meiotic division, resulting in the accumulation of high energy protein phosphate by second metaphase arrest. 31P-NMR, with saturation transfer, demonstrates that the phosphocreatine level rises ~2 fold and that the "pseudo" first order rate constant for the creatine kinase reaction falls to ~20

SUBMITTER: Morrill GA 

PROVIDER: S-EPMC3248852 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature