Phosphorylation of Xenopus cyclins B1 and B2 is not required for cell cycle transitions.

Izumi, Tetsuro; Maller, James L.

doi:10.1128/mcb.11.8.3860

Cited by 89 publications

(75 citation statements)

References 41 publications

(60 reference statements)

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“…One preparation was termed EGF receptor threonine 669 kinase; it now appears to be identical to human p44/ERK1 Our studies provide direct evidence in support of the same conclusion. The sequence around serine 243, P-L-S-P, satisfies an emerging consensus for p42 and p44 MAP kinase phosphorylation sites, P-X-S/T-P (Erickson et al, 1990;Alvarez et al, 1991;Gonzalez et al, 1991;Izumi and Maller, 1991;Takishima et al, 1991;Mukhopadhyay et al, 1992). Other nonpolar residues may be able to substitute for the upstream proline (Haycock et al, 1992).…”

Section: Discussionmentioning

confidence: 99%

Inhibition of c-Jun DNA binding by mitogen-activated protein kinase.

Baichwal

Ferrell

1992

MBoC

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Here we demonstrate that partially purified Xenopus p42 mitogen-activated protein (MAP) kinase phosphorylates bacterially expressed human c-Jun at a single site, serine 243. Several lines of evidence argue that this phosphorylation is due to p42 MAP kinase itself rather than some contaminating species. Phosphorylation of serine 243 markedly decreases the binding of c-Jun to oligonucleotides containing the 12-O-tetradecanoylphorbol-13-acetate response element. These findings suggest that MAP kinase may play a role in the down-regulation of c-Jun or in the cycle of transcriptional initiation and elongation.

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Section: Discussionmentioning

confidence: 99%

Inhibition of c-Jun DNA binding by mitogen-activated protein kinase.

Baichwal

Ferrell

1992

MBoC

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“…Xenopus oocyte cyclin B1 has been shown to undergo phosphorylation in vitro with MAPK or Cdc2/cyclin B on five sites, identified as Ser 2, Ser 94, Ser 96, Ser 101 and Ser 113 (Izumi and Maller, 1991;Li et al, 1995). The importance of phosphorylation at these sites in Xenopus cyclin B1 has not been established.…”

Section: Phosphorylation Of Cyclin Bmentioning

confidence: 99%

“…Entry into mitosis depends on phosphorylation of the dualspecificity phosphatase Cdc25C, which dephosphorylates Cdc2 on Tyr15 and Thr14, and hence, activates the Cdc2/cyclin B complex that catalyses the G 2 /M transition (Dunphy and Kumagai, 1991;Izumi and Maller, 1991). Although Cdc2/cyclin B itself is able to phosphorylate Cdc25C at the activating sites, forming a positive feedback loop (Izumi and Maller, 1993), the initial phosphorylation of Cdc25C occurs before Cdc2/ cyclin B activation at the G 2 /M transition (Qian et al, 1998a).…”

Section: Phosphorylation Of Cdc25cmentioning

confidence: 99%

Xenopus Polo-like kinase Plx1: a multifunctional mitotic kinase

Liu

Maller

2005

Oncogene

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“…The residues phosphorylated in cyclin B 1 have been identified in Xenopus: Ser-2, Ser-94, Ser-96, Ser-101, and Ser-113 (32,33). Mutational studies (29,32,33) have suggested that cyclin B phosphorylation is required neither for activity of the Cdc2 kinase, for Cdc2 binding, nor for cyclin B destruction in anaphase.…”

mentioning

confidence: 99%

“…The residues phosphorylated in cyclin B 1 have been identified in Xenopus: Ser-2, Ser-94, 33). Mutational studies (29,32,33) have suggested that cyclin B phosphorylation is required neither for activity of the Cdc2 kinase, for Cdc2 binding, nor for cyclin B destruction in anaphase. More recently, Li et al (34) showed that if the residues were mutated to nonphosphorylatable residues, the Cdc2-cyclin B complex does not migrate from the cytoplasm to the nucleus and therefore loses its MPF activity.…”

mentioning

confidence: 99%

Intra-M Phase-promoting Factor Phosphorylation of Cyclin B at the Prophase/Metaphase Transition

Borgne¹,

Østvold²,

Flament³

et al. 1999

Journal of Biological Chemistry

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in vivo phosphorylation as shown by phosphopeptide maps of in vivo and in vitro phosphorylated cyclin B. We demonstrate that Cdc2 itself is the cyclin B kinase; cyclin B phosphorylation requires Cdc2 activity both in vivo (sensitivity to vitamin K 3 , a Cdc25 inhibitor) and in vitro (copurification with Cdc2-cyclin B, requirement of Cdc2 dephosphorylation, and sensitivity to chemical inhibitors of cyclin-dependent kinases). Furthermore, cyclin B phosphorylation occurs as an intra-M phase-promoting factor reaction as shown by the following: 1) active Cdc2 is unable to phosphorylate cyclin B associated to phosphorylated Cdc2, and 2) cyclin B phosphorylation is insensitive to enzyme/substrate dilution. We conclude that, at the prophase/metaphase transition, cyclin B is mostly phosphorylated by its own associated Cdc2 subunit.Cell cycle events are regulated by the cyclin-dependent kinases (CDKs) 1 (for reviews, see Refs. 1-5). Cyclins are responsible for kinase activation, substrate specificity, and intracellular localization (6). The key regulator of the G 2 /M transition is the M phase-promoting factor (MPF), a complex constituted of the catalytic subunit p34 cdc2 (7-9) and the regulatory subunit cyclin B cdc13 (6, 10 -11). Activation of MPF at the onset of mitosis is associated with modifications of phosphorylation of its two subunits (11-13). In late prophase, Cdc2 is phosphorylated on three residues: Thr-14, Tyr-15, and Thr-161. Thr-161 phosphorylation is catalyzed by the Cdc2-activating kinase identified as a complex between Cdk7 (MO15), cyclin H, and MAT1 (14). This phosphorylation is necessary for Cdc2 activity (15, 16). The Thr-14 and Tyr-15 residues of Cdc2 are located in the ATP-binding pocket of the kinase (17). Following cyclin B binding to Cdc2 (6,12,18), Cdc2 becomes phosphorylated on Thr-14 by the Myt1 kinase (19,20) and on Tyr-15 by the Wee1/Mik1 or Myt1 kinases (20 -22). In yeast, only Tyr-15 is phosphorylated in G 2 (23). Cdc2 activation at prophase/metaphase transition requires dephosphorylation of both Thr-14 and Tyr-15. These dephosphorylations occur in two successive steps: first Thr-14 and then . The Cdc25 dual-specificity phosphatase dephosphorylates both residues (reviewed in Ref. 25). The Pyp3 tyrosine phosphatase acts on Tyr-15 in fission yeast (26). A positive feedback loop originating from Cdc2 leads to the autocatalytic amplification of the complex (27,28). This is possibly partially generated by the singly phosphorylated form of Cdc2, dephosphorylated on Thr-14/ phosphorylated on Tyr-15 (24).Simultaneously with Cdc2 dephosphorylation, cyclin B becomes phosphorylated as described in a variety of models such as yeast (6), starfish oocytes (13), sea urchin eggs (11), goldfish oocytes (29), Xenopus oocytes (30), and human cells (31). The residues phosphorylated in cyclin B 1 have been identified in Xenopus: Ser-2, Ser-94, 33). Mutational studies (29,32,33) have suggested that cyclin B phosphorylation is required neither for activity of the Cdc2 kinase, for Cdc2 binding, nor for cyclin B d...

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Phosphorylation of Xenopus cyclins B1 and B2 is not required for cell cycle transitions.

Cited by 89 publications

References 41 publications

Inhibition of c-Jun DNA binding by mitogen-activated protein kinase.

Inhibition of c-Jun DNA binding by mitogen-activated protein kinase.

Xenopus Polo-like kinase Plx1: a multifunctional mitotic kinase

Intra-M Phase-promoting Factor Phosphorylation of Cyclin B at the Prophase/Metaphase Transition

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