Crystal structure of the p27Kip1 cyclin-dependent-kinase inibitor bound to the cyclin A–Cdk2 complex

Abstract In humans, the molecular mechanisms underlying ovarian follicle endowment and activation, which are closely related to the control of female reproduction, occurrence of menopause, and related diseases such as premature ovarian failure, are poorly understood. In the current study, we provide several lines of genetic evidence that the cyclin-dependent kinase (Cdk) inhibitor 1B (commonly known as p27kip1 or p27) controls ovarian development in mice by suppressing follicle endowment and activation, and by promoting follicle death. In p27-deficient (p27−/−) mice, postnatal follicle assembly was accelerated, and the number of endowed follicles was doubled as compared with p27+/+ mice. Moreover, in p27−/− ovaries the primordial follicle pool was prematurely activated once it was endowed, and at the same time the massive follicular death that occurs before sexual maturity was rescued by loss of p27. In early adulthood, however, the overactivated follicular pool in p27−/− ovaries was largely depleted, causing premature ovarian failure. Furthermore, we have extensively studied the molecular mechanisms underlying the above-mentioned phenotypes seen in p27−/− ovaries and have found that p27 controls follicular development by several distinct mechanisms at different stages of development of the ovary. For example, p27 controls oocyte growth by suppressing the functions of Cdk2/Cdc2-cyclin A/E1 in oocytes that are arrested at the diplotene stage of meiosis I. This function of p27 is distinct from its well-known role as a suppressor of cell cycle progression. In addition, we have found that p27 activates the caspase-9-caspase-3-caspase-7-poly (ADP-ribose) polymeraseapoptotic cascade by inhibiting Cdk2/Cdc2-cyclin A/B1 kinase activities in follicles, thereby inducing follicle atresia. Our results suggest that the p27 gene is important in determining mammalian ovarian development. This study therefore provides insight into ovary-borne genetic aberrations that cause defects in folliculogenesis and infertility in humans.

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Identification of distinct roles for separate E1A domains in disruption of E2F complexes

Molecular and Cellular Biology ◽

10.1128/mcb.13.11.7029-7035.1993 ◽

1993 ◽

Vol 13 (11) ◽

pp. 7029-7035

Author(s):

M A Ikeda ◽

J R Nevins

Keyword(s):

Transcription Factor ◽

Gene Product ◽

Protein Complexes ◽

Cyclin A ◽

Regulatory Proteins ◽

Retinoblastoma Gene ◽

Adenovirus E1a ◽

E2f Transcription Factor ◽

Cdk2 Complex ◽

Equilibrium Dissociation

The adenovirus E1A protein can disrupt protein complexes containing the E2F transcription factor in association with cellular regulatory proteins such as the retinoblastoma gene product (Rb) and the Rb-related p107 protein. Previous experiments have shown that the CR1 and CR2 domains of E1A are required for this activity. We now demonstrate that the CR2 domain is essential for allowing E1A to interact with the E2F-Rb or the E2F-p107-cyclin A-cdk2 complex. Multimeric complexes containing E1A can be detected when the CR1 domain has been rendered inactive by mutation. In addition, the E1A CR1 domain, but not the CR2 domain, is sufficient to prevent the interaction of E2F with Rb or p107. On the basis of these results, we suggest a model whereby the CR2 domain brings E1A to the E2F complexes and then, upon a normal equilibrium dissociation of Rb or p107 from E2F, the E1A CR1 domain is able to block the site of interaction on Rb or p107, thereby preventing the re-formation of the complexes.

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Acetylation of cyclin A: a new cell cycle regulatory mechanism

Biochemical Society Transactions ◽

10.1042/bst0380083 ◽

2010 ◽

Vol 38 (1) ◽

pp. 83-86 ◽

Cited By ~ 13

Author(s):

Francesca Mateo ◽

Miriam Vidal-Laliena ◽

Maria Jesus Pujol ◽

Oriol Bachs

Keyword(s):

Binding Protein ◽

Cyclin A ◽

Camp Response Element Binding ◽

Cyclin Dependent Kinase ◽

General Control ◽

Camp Response Element ◽

Lysine Residues ◽

Subsequent Degradation ◽

The Status ◽

Element Binding Protein

Cyclin A must be degraded at prometaphase in order to allow mitosis progression. Nevertheless, the signals that trigger cyclin A degradation at mitosis have been largely elusive. In the present paper, we review the status of cyclin A degradation in the light of recent evidence indicating that acetylation plays a role in cyclin A stability. The emerging model proposes that the acetyltransferase PCAF [p300/CREB (cAMP-response-element-binding protein)-binding protein-associated factor] [perhaps also its homologue GCN5 (general control non-derepressible 5)] acetylates cyclin A at Lys54, Lys68, Lys95 and Lys112 during mitosis, leading to its ubiquitylation by the anaphase-promoting factor/cyclosome and its subsequent degradation via proteasome. Interestingly, these four lysine residues in cyclin A also participate in the regulation of cyclin A–Cdk (cyclin-dependent kinase) activity by modulating its interaction with Cdks.

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Crystal Structure of Human Cyclin-Dependent Kinase 2 in Complex with the Adenine-Derived Inhibitor H717

Journal of Medicinal Chemistry ◽

10.1021/jm001043t ◽

2001 ◽

Vol 44 (4) ◽

pp. 524-530 ◽

Cited By ~ 38

Author(s):

Matthias K. Dreyer ◽

David R. Borcherding ◽

Jennifer A. Dumont ◽

Norton P. Peet ◽

Joseph T. Tsay ◽

...

Keyword(s):

Crystal Structure ◽

Cyclin Dependent Kinase

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Identification of a cyclin-cdk2 recognition motif present in substrates and p21-like cyclin-dependent kinase inhibitors.

Molecular and Cellular Biology ◽

10.1128/mcb.16.12.6623 ◽

1996 ◽

Vol 16 (12) ◽

pp. 6623-6633 ◽

Cited By ~ 247

Author(s):

P D Adams ◽

W R Sellers ◽

S K Sharma ◽

A D Wu ◽

C M Nalin ◽

...

Keyword(s):

Kinase Inhibitors ◽

Cyclin A ◽

Cdk Inhibitors ◽

Cyclin Dependent Kinase ◽

Binding Motifs ◽

Recognition Motif ◽

Binding Inhibition ◽

In Vivo Growth

Understanding how cyclin-cdk complexes recognize their substrates is a central problem in cell cycle biology. We identified an E2F1-derived eight-residue peptide which blocked the binding of cyclin A and E-cdk2 complexes to E2F1 and p21. Short peptides spanning similar sequences in p107, p130, and p21-like cdk inhibitors likewise bound to cyclin A-cdk2 and cyclin E-cdk2. In addition, these peptides promoted formation of stable cyclin A-cdk2 complexes in vitro but inhibited the phosphorylation of the retinoblastoma protein by cyclin A- but not cyclin B-associated kinases. Mutation of the cyclin-cdk2 binding motifs in p107 and E2F1 likewise prevented their phosphorylation by cyclin A-associated kinases in vitro. The cdk inhibitor p21 was found to contain two functional copies of this recognition motif, as determined by in vitro kinase binding/inhibition assays and in vivo growth suppression assays. Thus, these studies have identified a cyclin A- and E-cdk2 substrate recognition motif. Furthermore, these data suggest that p21-like cdk inhibitors function, at least in part, by blocking the interaction of substrates with cyclin-cdk2 complexes.

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Human Cyclin a Is Required for Mitosis until Mid Prophase

The Journal of Cell Biology ◽

10.1083/jcb.147.2.295 ◽

1999 ◽

Vol 147 (2) ◽

pp. 295-306 ◽

Cited By ~ 148

Author(s):

Nobuaki Furuno ◽

Nicole den Elzen ◽

Jonathon Pines

Keyword(s):

Cyclin A ◽

Time Lapse ◽

S Phase ◽

Early Prophase ◽

Cyclin Dependent Kinase ◽

Late Prophase ◽

Daughter Cells ◽

G2 Phase ◽

Rate Limiting

We have used microinjection and time-lapse video microscopy to study the role of cyclin A in mitosis. We have injected purified, active cyclin A/cyclin-dependent kinase 2 (CDK2) into synchronized cells at specific points in the cell cycle and assayed its effect on cell division. We find that cyclin A/CDK2 will drive G2 phase cells into mitosis within 30 min of microinjection, up to 4 h before control cells enter mitosis. Often this premature mitosis is abnormal; the chromosomes do not completely condense and daughter cells fuse. Remarkably, microinjecting cyclin A/CDK2 into S phase cells has no effect on progress through the following G2 phase or mitosis. In complementary experiments we have microinjected the amino terminus of p21Cip1/Waf1/Sdi1 (p21N) into cells to inhibit cyclin A/CDK2 activity. We find that p21N will prevent S phase or G2 phase cells from entering mitosis, and will cause early prophase cells to return to interphase. These results suggest that cyclin A/CDK2 is a rate-limiting component required for entry into mitosis, and for progress through mitosis until late prophase. They also suggest that cyclin A/CDK2 may be the target of the recently described prophase checkpoint.

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