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.
Dephosphorylation of sperm midpiece antigens initiates aster formation in rabbit oocytes.
Pinto-Correia C
,
Poccia DL
,
Chang T
,
Robl JM
.
???displayArticle.abstract???
During fertilization in most mammals, the penetrating sperm organizes an aster of microtubules. We have investigated the mechanisms underlying this function of the sperm by a series of experiments based on microinjection of isolated sperm midpieces into unfertilized oocytes. These midpieces contain antigens recognized by the MPM-2 antibody. These antigens, which are absent from the rest of the tail fraction, correspond to three phosphorylated polypeptides of 77, 81, and 85 kDa. Dephosphorylation with alkaline phosphatase abolishes antigenicity on blots and in whole sperm. Reactivity to the antibody disappears between 1 and 3 hr after calcium stimulation of oocytes, following the decline in H1 kinase activity and coincident with aster formation. In unactivated oocytes, no aster forms and the antigen remains unchanged. MPM-2 treatment of midpieces prior to injection blocks their ability to form asters in oocytes activated by calcium stimulation. The epitope also disappears in 6-methyl-aminopurine-treated oocytes, implying that maintenance of the phosphorylated state requires kinase activity. A result that confirms this view is that sperm midpieces dephosphorylated by alkaline phosphatase can be rephosphorylated after injection into oocytes or by exposure in vitro to a Xenopus oocyte cytoplasmic fraction high in H1 kinase activity. We suggest that the microtubule nucleation activity of sperm midpieces after fertilization is triggered by the calcium-induced decrease in maturation promoting factor, which results in dephosphorylation of specific sperm centrosomal proteins.
Centonze,
Nucleation of microtubules from mitotic centrosomes is modulated by a phosphorylated epitope.
1990, Pubmed
Centonze,
Nucleation of microtubules from mitotic centrosomes is modulated by a phosphorylated epitope.
1990,
Pubmed
Collas,
Influence of cell cycle stage of the donor nucleus on development of nuclear transplant rabbit embryos.
1992,
Pubmed
Collas,
Effect of donor cell cycle stage on chromatin and spindle morphology in nuclear transplant rabbit embryos.
1992,
Pubmed
Collas,
Histone H1 kinase activity in bovine oocytes following calcium stimulation.
1993,
Pubmed
Crozet,
Behavior of the sperm centriole during sheep oocyte fertilization.
1990,
Pubmed
Davis,
Monoclonal antibodies to mitotic cells.
1983,
Pubmed
,
Xenbase
Fawcett,
The fine structure and development of the neck region of the mammalian spermatozoon.
1969,
Pubmed
Fissore,
Intracellular Ca2+ response of rabbit oocytes to electrical stimulation.
1992,
Pubmed
Kuang,
Mitosis-specific monoclonal antibody MPM-2 inhibits Xenopus oocyte maturation and depletes maturation-promoting activity.
1989,
Pubmed
,
Xenbase
Kubiak,
The metaphase II arrest in mouse oocytes is controlled through microtubule-dependent destruction of cyclin B in the presence of CSF.
1993,
Pubmed
Kuriyama,
Immunocytochemical evidence for centrosomal phosphoproteins in mitotic sea urchin eggs.
1990,
Pubmed
Lewin,
Driving the cell cycle: M phase kinase, its partners, and substrates.
1990,
Pubmed
Maggi,
Progesterone-binding sites of the chick oviduct receptor. Presence of a weaker ligand site which is destroyed by phosphatase treatment.
1984,
Pubmed
Rime,
6-Dimethylaminopurine (6-DMAP), a reversible inhibitor of the transition to metaphase during the first meiotic cell division of the mouse oocyte.
1989,
Pubmed
Sathananthan,
Centrioles in the beginning of human development.
1991,
Pubmed
Schatten,
Behavior of centrosomes during fertilization and cell division in mouse oocytes and in sea urchin eggs.
1986,
Pubmed
Stice,
Activation of mammalian oocytes by a factor obtained from rabbit sperm.
1990,
Pubmed
Szollosi,
Absence of centrioles in the first and second meiotic spindles of mouse oocytes.
1972,
Pubmed
Vandré,
Anaphase onset and dephosphorylation of mitotic phosphoproteins occur concomitantly.
1989,
Pubmed
Vandré,
Proteins of the mammalian mitotic spindle: phosphorylation/dephosphorylation of MAP-4 during mitosis.
1991,
Pubmed
Vandré,
Immunoelectron microscopic localization of phosphoproteins associated with the mitotic spindle.
1992,
Pubmed
Whitaker,
Calcium and cell cycle control.
1990,
Pubmed
Yllera-Fernández,
Microtubule distribution during fertilization in the rabbit.
1992,
Pubmed
