Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Bub1 is activated by the protein kinase p90(Rsk) during Xenopus oocyte maturation
Autore:
Schwab, MS; Roberts, BT; Gross, SD; Tunquist, BJ; Taieb, FE; Lewellyn, AL; 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: 3, volume: 11, anno: 2001,
pagine: 141 - 150
SICI:
0960-9822(20010206)11:3<141:BIABTP>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
SPINDLE ASSEMBLY CHECKPOINT; ANAPHASE-PROMOTING COMPLEX; DUPLICATION GENE MPS1; CELL-CYCLE EXTRACTS; SACCHAROMYCES-CEREVISIAE; MAP KINASE; KINETOCHORE LOCALIZATION; MITOTIC CHECKPOINT; CHROMOSOME CYCLES; METAPHASE ARREST;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
50
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:
M.S. Schwab et al., "Bub1 is activated by the protein kinase p90(Rsk) during Xenopus oocyte maturation", CURR BIOL, 11(3), 2001, pp. 141-150

Abstract

Background: The kinetochore attachment (spindle assembly) checkpoint arrests cells in metaphase to prevent exit from mitosis until all the chromosomes are aligned properly at the metaphase plate. The checkpoint operates by preventing activation of the anaphase-promoting complex (APC), which triggers anaphase by degrading mitotic cyclins and other proteins. This checkpointis active during normal mitosis and upon experimental disruption of the mitotic spindle, In yeast, the serine/threonine protein kinase Bub1 and the WD-repeat protein Bub3 are elements of a signal transduction cascade that regulates the kinetochore attachment checkpoint. In mammalian cells, activated MAPK is present on kinetochores during mitosis and activity is upregulated by the spindle assembly checkpoint. In vertebrate unfertilized eggs, a special form of meiotic metaphase arrest by cytostatic factor (CSF) is mediated by MAPK activation of the protein kinase p90(Rsk), which leads to inhibition of the APC, However, it is not known whether CSF-dependent metaphase arrest caused by p90(Rsk) involves components of the spindle assembly checkpoint. Results: xBub1 is present in resting oocytes and its protein level increases slightly during oocyte maturation and early embryogenesis. In Xenopus oocytes, Bub1 is localized to kinetochores during both meiosis I and meiosis II, and the electrophoretic mobility of Bubl upon SDS-PAGE decreases duringmeiosis I, reflecting phosphorylation and activation of the enzyme. The activation of Bubl can be induced in interphase egg extracts by selective stimulation of the MAPK pathway by c-Mos, a MAPKKK. In oocytes treated with the MEK1 inhibitor U0126, the MAPK pathway does not become activated, and Bubl remains in its low-activity, unshifted form. Injection of a constitutively active target of MAPK, the protein kinase p90(Rsk), restores the activation of Bubl in the presence of U0126. Moreover, purified p90(Rsk) phosphorylates Bubl in vitro and increases its protein kinase activity. Conclusions: Bubl, an upstream component of the kinetochore attachment checkpoint, is activated during meiosis in Xenopus in a MAPK-dependent manner. Moreover, a single substrate of MAPK, p90(Rsk), is, sufficient to activateBubl in vitro and in vivo. These results indicate that in vertebrate eggs,kinetochore attachment/spindle assembly checkpoint proteins, including Bubl, are downstream of p90(Rsk) and may be effecters of APC inhibition and CSF-dependent metaphase arrest by p90(Rsk).

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/11/20 alle ore 22:14:06