Biomaterial Database

Stimulatory effect of okadaic acid, an inhibitor of protein phosphatases, on nuclear envelope breakdown and protein phosphorylation in mouse oocytes and one-cell embryos. 1991

D A Schwartz, and R M Schultz

Department of Biology, University of Pennsylvania, Philadelphia 19104-6018.

Treatment of one-cell mouse embryos with okadaic acid (OA), which is an inhibitor of protein phosphatases 1 and 2A, induces a concentration-dependent precocious nuclear envelope breakdown (NEBD) of the pronuclei; at 10 microM okadaic acid, NEBD starts to occur after 1 hr and the embryos become committed to NEBD after about 45 min. Correlated with NEBD is the conversion of a protein of Mr 32,000 (p32) to more highly phosphorylated forms. One-cell embryos cultured continuously in OA-containing medium do not cleave, whereas one-cell embryos incubated for 15-60 min prior to transfer to OA-free medium reveal a time-dependent inhibition in their ability to cleave. OA treatment of oocytes that are arrested from resuming spontaneous maturation by either a phosphodiesterase inhibitor or biologically active phorbol diester results in germinal vesicle breakdown and the maturation-associated changes in the pattern of protein phosphorylation, which include the apparent phosphorylation of p32. Results of these experiments implicate protein phosphatases in the G2 to M transition of the cell cycle in both meiotic and mitotic cells.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008715	Methionine	A sulfur-containing essential L-amino acid that is important in many body functions.	L-Methionine,Liquimeth,Methionine, L-Isomer,Pedameth,L-Isomer Methionine,Methionine, L Isomer
D008815	Mice, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.	Inbred Mouse Strains,Inbred Strain of Mice,Inbred Strain of Mouse,Inbred Strains of Mice,Mouse, Inbred Strain,Inbred Mouse Strain,Mouse Inbred Strain,Mouse Inbred Strains,Mouse Strain, Inbred,Mouse Strains, Inbred,Strain, Inbred Mouse,Strains, Inbred Mouse
D009685	Nuclear Envelope	The membrane system of the CELL NUCLEUS that surrounds the nucleoplasm. It consists of two concentric membranes separated by the perinuclear space. The structures of the envelope where it opens to the cytoplasm are called the nuclear pores (NUCLEAR PORE).	Nuclear Membrane,Envelope, Nuclear,Envelopes, Nuclear,Membrane, Nuclear,Membranes, Nuclear,Nuclear Envelopes,Nuclear Membranes
D009865	Oocytes	Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).	Ovocytes,Oocyte,Ovocyte
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D010749	Phosphoprotein Phosphatases	A group of enzymes removing the SERINE- or THREONINE-bound phosphate groups from a wide range of phosphoproteins, including a number of enzymes which have been phosphorylated under the action of a kinase. (Enzyme Nomenclature, 1992)	Phosphoprotein Phosphatase,Phosphoprotein Phosphohydrolase,Protein Phosphatase,Protein Phosphatases,Casein Phosphatase,Ecto-Phosphoprotein Phosphatase,Nuclear Protein Phosphatase,Phosphohistone Phosphatase,Phosphoprotein Phosphatase-2C,Phosphoseryl-Protein Phosphatase,Protein Phosphatase C,Protein Phosphatase C-I,Protein Phosphatase C-II,Protein Phosphatase H-II,Protein-Serine-Threonine Phosphatase,Protein-Threonine Phosphatase,Serine-Threonine Phosphatase,Threonine Phosphatase,Ecto Phosphoprotein Phosphatase,Phosphatase C, Protein,Phosphatase C-I, Protein,Phosphatase C-II, Protein,Phosphatase H-II, Protein,Phosphatase, Casein,Phosphatase, Ecto-Phosphoprotein,Phosphatase, Nuclear Protein,Phosphatase, Phosphohistone,Phosphatase, Phosphoprotein,Phosphatase, Phosphoseryl-Protein,Phosphatase, Protein,Phosphatase, Protein-Serine-Threonine,Phosphatase, Protein-Threonine,Phosphatase, Serine-Threonine,Phosphatase, Threonine,Phosphatase-2C, Phosphoprotein,Phosphatases, Phosphoprotein,Phosphatases, Protein,Phosphohydrolase, Phosphoprotein,Phosphoprotein Phosphatase 2C,Phosphoseryl Protein Phosphatase,Protein Phosphatase C I,Protein Phosphatase C II,Protein Phosphatase H II,Protein Phosphatase, Nuclear,Protein Serine Threonine Phosphatase,Protein Threonine Phosphatase,Serine Threonine Phosphatase
D010750	Phosphoproteins		Phosphoprotein
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D001755	Blastocyst	A post-MORULA preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper.	Embryo, Preimplantation,Blastocysts,Embryos, Preimplantation,Preimplantation Embryo,Preimplantation Embryos