Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Abstract
The calcium-binding protein, calmodulin, has been purified from Xenopus laevis oocytes. This 18,500-dalton protein, pl 4.3, has two high-affinity calcium-binding sites per mole protein having a dissociation constant of 2.8 x 10(-6) M. Full-grown Xenopus oocytes, arrested in late G2 of the meiotic cell cycle, resumed meiosis when microinjected with 60-80 ng (3-4 pmol) of calmodulin in the form of a calcium-calmodulin complex. The timing of the meiotic events in these recipient oocytes was the same as that normally induced by progesterone. Xenopus ovarian calmodulin stimulated bovine brain phosphodiesterase (PDE) 3- to 10-fold in a calcium-dependent manner, but it had no apparent effect on ovarian PDE activity. A calcium-calmodulin-dependent protein kinase has been isolated from Xenopus oocytes using a calmodulin-Sepharose 4B affinity column. The possible role for this kinase in regulating the G2-M transition in oocytes has been discussed.
Baulieu,
Steroid-induced meiotic division in Xenopus laevis oocytes: surface and calcium.
1978, Pubmed,
Xenbase
Baulieu,
Steroid-induced meiotic division in Xenopus laevis oocytes: surface and calcium.
1978,
Pubmed
,
Xenbase
Cartaud,
Xenopus laevis oocyte calmodulin in the process of meiotic maturation.
1980,
Pubmed
,
Xenbase
Cheung,
Calmodulin plays a pivotal role in cellular regulation.
1980,
Pubmed
Childers,
Isolation and purification of calcium-binding protein from electroplax of Electrophorus electricus.
1975,
Pubmed
Dedman,
Physicochemical properties of rat testis Ca2+-dependent regulator protein of cyclic nucleotide phosphodiesterase. Relationship of Ca2+-binding, conformational changes, and phosphodiesterase activity.
1977,
Pubmed
Head,
Calcium-binding modulator protein from the unfertilized egg of the sea urchin Arbacia punctulata.
1979,
Pubmed
Klee,
Purification of cyclic 3',5'-nucleotide phosphodiesterase inhibitory protein by affinity chromatography on activator protein coupled to Sepharose.
1978,
Pubmed
Klee,
Calmodulin.
1980,
Pubmed
Lin,
Cyclic 3':5'-nucleotide phosphodiesterase. Purification, characterization, and active form of the protein activator from bovine brain.
1974,
Pubmed
Maller,
Progesterone-stimulated meiotic cell division in Xenopus oocytes. Induction by regulatory subunit and inhibition by catalytic subunit of adenosine 3':5'-monophosphate-dependent protein kinase.
1977,
Pubmed
,
Xenbase
Maller,
Changes in protein phosphorylation accompanying maturation of Xenopus laevis oocytes.
1977,
Pubmed
,
Xenbase
Maller,
Early effect of progesterone on levels of cyclic adenosine 3':5'-monophosphate in Xenopus oocytes.
1979,
Pubmed
,
Xenbase
Maller,
Regulation of oocyte maturation.
1980,
Pubmed
,
Xenbase
Masui,
Cytoplasmic control of nuclear behavior during meiotic maturation of frog oocytes.
1971,
Pubmed
Masui,
Roles of divalent cations in maturation and activation of vertebrate oocytes.
1977,
Pubmed
,
Xenbase
Means,
Calmodulin--an intracellular calcium receptor.
1980,
Pubmed
Moreau,
Electrophoretic introduction of calcium ions into the cortex of Xenopus laevis oocytes triggers meiosis neinitiation.
1976,
Pubmed
,
Xenbase
Morrill,
Changes in cyclic AMP levels in the amphibian ovarian follicle following progesterone induction of meiotic maturation. Effect of phosphodiesterase inhibitors and exogenous calcium on germinal vesicle breakdown.
1977,
Pubmed
O'Connor,
Inhibition of oocyte maturation by theophylline: possible mechanism of action.
1976,
Pubmed
,
Xenbase
RAAFLAUB,
Applications of metal buffers and metal indicators in biochemistry.
1956,
Pubmed
Sanui,
Measurement of inorganic orthophosphate in biological materials: extraction properties of butyl acetate.
1974,
Pubmed
Schulman,
Ca2+-dependent protein phosphorylation system in membranes from various tissues, and its activation by "calcium-dependent regulator".
1978,
Pubmed
Speaker,
Cyclic nucleotide fluctuations during steroid induced meiotic maturation of frog oocytes.
1977,
Pubmed
Waisman,
Purification and characterization of a Ca2+-binding protein in Lumbricus terrestris.
1978,
Pubmed
Wallace,
Protein incorporation by isolated amphibian oocytes. 3. Optimum incubation conditions.
1973,
Pubmed
,
Xenbase
Wasserman,
Initiation of meiotic maturation in Xenopus laevis oocytes by the combination of divalent cations and ionophore A23187.
1975,
Pubmed
,
Xenbase
Wasserman,
Progesterone induces a rapid increase in [Ca2+]in of Xenopus laevis oocytes.
1980,
Pubmed
,
Xenbase
Watterson,
Structural similarities between the Ca2+-dependent regulatory proteins of 3':5'-cyclic nucleotide phosphodiesterase and actomyosin ATPase.
1976,
Pubmed
Welsh,
Calcium-dependent regulator protein: localization in mitotic apparatus of eukaryotic cells.
1978,
Pubmed
