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Titolo:
The critical role of the MAP kinase pathway in meiosis II in Xenopus oocytes is mediated by p90(Rsk)
Autore:
Gross, SD; Schwab, MS; Taieb, FE; Lewellyn, AL; Qian, YW; Maller, JL;
Indirizzi:
Univ Colorado, Sch Med, Howard Hughes Med Inst, Denver, CO 80262 USA Univ Colorado Denver CO USA 80262 d Hughes Med Inst, Denver, CO 80262 USA Univ Colorado, Sch Med, Dept Pharmacol, Denver, CO 80262 USA Univ Colorado Denver CO USA 80262 d, Dept Pharmacol, Denver, CO 80262 USA
Titolo Testata:
CURRENT BIOLOGY
fascicolo: 8, volume: 10, anno: 2000,
pagine: 430 - 438
SICI:
0960-9822(20000420)10:8<430:TCROTM>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
MOS PROTO-ONCOGENE; CELL-FREE SYSTEM; MEIOTIC MATURATION; CYCLIN-B; INHIBITORY KINASE; METAPHASE ARREST; ACTIVATION; EGGS; PHOSPHORYLATES; DESTRUCTION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
44
Recensione:
Indirizzi per estratti:
Indirizzo: Maller, JL Univ Colorado, Sch Med, Howard Hughes Med Inst, 4200 E 9th Ave,Denver, CO80262 USA Univ Colorado 4200 E 9th Ave Denver CO USA 80262 r, CO80262 USA
Citazione:
S.D. Gross et al., "The critical role of the MAP kinase pathway in meiosis II in Xenopus oocytes is mediated by p90(Rsk)", CURR BIOL, 10(8), 2000, pp. 430-438

Abstract

Background: During oocyte maturation in Xenopus, progesterone induces entry into meiosis I, and the M phases of meiosis I and II occur consecutively without an intervening S phase. The mitogen-activated protein (MAP) kinase is activated during meiotic entry, and it has been suggested that the linkage of M phases reflects activation of the MAP kinase pathway and the failure to fully degrade cyclin B during anaphase I. To analyze the function of the MAP kinase pathway in oocyte maturation, we used U0126, a potent inhibitor of MAP kinase kinase, and a constitutively active mutant of the protein kinase p90(Rsk), a MAP kinase target. Results: Even with complete inhibition of the MAP kinase pathway by U0126,up to 90% of oocytes were able to enter meiosis I after progesterone treatment, most likely through activation of the phosphatase Cdc25C by the polo-like kinase Plx1. Subsequently, however, U0126-treated oocytes failed to form metaphase I spindles, failed to reaccumulate cyclin B to a high level and failed to hyperphosphorylate Cdc27, a component of the anaphase-promotingcomplex (APC) that controls cyclin B degradation. Such oocytes entered S phase rather than meiosis II. U0126-treated oocytes expressing a constitutively active form of p90(Rsk) were able to reaccumulate cyclin B, hyperphosphorylate Cdc27 and form metaphase spindles in the absence of detectable MAP kinase activity. Conclusions: The MAP kinase pathway is not essential for entry into meiosis I in Xenopus but is required during the onset of meiosis II to suppress entry into S phase, to regulate the APC so as to support cyclin B accumulation, and to support spindle formation. Moreover, one substrate of MAP kinase, p90(Rsk), is sufficient to mediate these effects during oocyte maturation.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/11/20 alle ore 09:52:07