These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Early increase of a 105,000-dalton phosphoprotein during meiotic maturation of Xenopus laevis oocyte.
    Author: Boyer J, Bellé R, Capony JP, Ozon R.
    Journal: Biochimie; 1983 Jan; 65(1):15-23. PubMed ID: 6299401.
    Abstract:
    In ovo [32P] phosphoproteins were analyzed during meiotic maturation of Xenopus laevis oocytes. A phosphoprotein of 105,000-dalton was found to increase early (one hour) after progesterone induction of meiosis. The pure heat-stable inhibitor (PKI) of cAMP-dependent protein kinase, which induces maturation, was microinjected into oocytes. Again the early increase in the 105,000-dalton [32P] phosphoprotein occurred. The burst in protein phosphorylation, which takes place at the period of germinal vesicle breakdown, was quantitatively and qualitatively comparable in progesterone and PKI-stimulated oocytes. In order to confirm the inverse relationship between the 105,000 dalton [32P] phosphoprotein increase and cAMP-dependent protein kinase activity, purified C-subunit of the kinase has been microinjected into oocytes. C-subunit which inhibits maturation did not increase significantly the 105,000-dalton [32P] phosphoprotein whereas it increased the total level of in ovo phosphorylation. Enucleation experiments favour the localization of the 105,000-dalton protein in both the oocyte cytoplasm and nucleus. Furthermore the progesterone-induced increase in the phosphorylation of the 105,000-dalton protein was found in the cytoplasmic compartment after oocyte enucleation.
    [Abstract] [Full Text] [Related] [New Search]