Growth Control and Cyclic Alterations of Cyclic AMP in the Cell Cycle

Burger, Max M.; Bombik, Bernd M.; Breckenridge, Bruce McL.; Sheppard, J. R.

doi:10.1038/newbio239161a0

Cited by 238 publications

(81 citation statements)

References 17 publications

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“…Oscillations of the cAMP-PKA pathway also mark the somatic cell cycle (23), and downregulation of PKA induces chromatin condensation in cultured fibroblasts (24). Finally, the presence of high concentrations of unreplicated DNA in Xenopus extracts inhibits the onset of mitosis and p34cdc2 tyrosine dephosphorylation (25,26).…”

Section: Methodsmentioning

confidence: 99%

A role for cAMP-dependent protein kinase in early embryonic divisions.

Grieco

Avvedimento

Gottesman

1994

Proc. Natl. Acad. Sci. U.S.A.

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The cAMP-dependent protein kinase (PKA) pathway affects cell cycle progression in "cycling" Xenopus egg extracts. The concentration of free PKA catalytic subunit oscillates during the cell cycle with a peak at the mitosisinterphase transition and a minimum at the onset of mitosis. Inhibition of endogenous PKA in interphase hastens the onset of mitosis. Stimulation of PKA induces interphase arrest, preventing the activation of the M-phase-promoting factor. PKA does not block the accumulation of cyclin or Its binding to p34wa, but the resultant complex lacks kinase actvity and p342 remains te-phosphorylated. PKA appears to stimulate an okadaic acid-sensitive serine/threonine phosphatase that acts upon cdc25. In this way PKA could downregulate the p34d tyrosine phosphatase activity of cdc25 and consequently block the activation of the M-phase-promoting factor.The progression through M and S phases in the early Xenopus embryo is regulated by cycles of activation and inactivation of the M-phase-promoting factor (MPF), a protein kinase composed of two subunits, cyclin B and p34cdc2 (1). During the cell cycle the concentration of the catalytic subunit (p34Cdc2) remains constant while cyclin accumulates from interphase to mitosis and is degraded at each metaphaseanaphase transition (2). In interphase, association with cyclin induces phosphorylation of p34cdc2 at key tyrosine and threonine residues. In this state the complex is enzymatically inactive (preMPF; refs. 3 and 4). At mitosis, the complex is dephosphorylated and activated by the Xenopus homologue of the Schizosaccharomyces pombe cdc25 protein (5-7). cdc25 undergoes serine/threonine phosphorylation at mitosis, which enhances its phosphatase activity (8-10). Since MPF can phosphorylate cdc25, an autoregulatory loop has been proposed in which, at mitosis, MPF phosphorylates and activates cdc25, which in turn dephosphorylates and further activates preMPF (10). In interphase, cdc25 is inactivated by an okadaic acid-sensitive phosphatase (8)(9)(10) (11,12). Inhibition of the cAMP-PKA pathway induces and PKA activation blocks meiotic maturation in many species (11, 13). In this paper we explore the role of PKA in the mitotic cell cycle, using cycling extracts (2) from activated Xenopus eggs. Our evidence suggests that oscillations in PKA activity regulate MPF activation via the cdc25 phosphatase pathway and help set the timing and progression of the embryonic cell cycle. MATERIALS AND METHODSExtract Preparation and PKA and Histone Hi Kinase Assays. Cycling, cytostatic factor-arrested (CSF), and interphase extracts were prepared from Xenopus eggs essentially as described (2, After incubation, samples (50 pu1) were put on ice and 25 /4 of packed p13-Sepharose beads was added. Washes were performed as described (3). p342 Immunoblot. p34cdc2 was affinity purified from 100 /4 of extract with p13-Sepharose beads. Samples were electrophoresed in an SDS/12% polyacrylamide gel and blotted onto a nitrocellulose filter (Amersham). The filter was then probed with an anti...

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Section: Methodsmentioning

confidence: 99%

A role for cAMP-dependent protein kinase in early embryonic divisions.

Grieco

Avvedimento

Gottesman

1994

Proc. Natl. Acad. Sci. U.S.A.

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“…5 and 6) that the differences in sensitivity to cytochalasin among cells of the same type are attributable to phase differences in their progression through the cell cycle, cells in G, being much more responsive than cells in S and G2 . Whether this can be correlated, in turn, with a specific parameter such as fluctuation in cyclic nucleotide content (13,82,113) remains to be demonstrated, but the evidence suggests an inverse correlation between responsiveness to CD and intracellular level of cyclic AMP . The inverse correlation between adhesiveness of the various cell types to substrate and their apparent responsiveness to CD may also be related to the differential responsiveness of individual cells .…”

Section: Dif Ferential Sensitivitymentioning

confidence: 99%

“…While firmly adherent to the substratum, the contracting cells retracted their extended peripheral cytoplasm centripetally, except for the multiple processes that anchored them to the surface or attached them to their neighbors (see Figs . 9,12,13) . Some 2-6 h later, in the continued presence of CD, the cytoplasm began to spread out in a thin layer and some of the multiple processes were withdrawn .…”

Section: Descriptive Overviewmentioning

confidence: 99%

Action of Cytochalasin D on Cells of Established Lines

Miranda

Godman

Deitch

et al. 1974

The Journal of Cell Biology

216

119

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HeLa, Vero, L, HEp2, and MDBK cells respond immediately to 0.2–0.5 µg/ml cytochalasin D (CD) with sustained contraction (contracture), loss of microvilli, expression of endoplasmic contents (zeiosis), nuclear protrusion, and extension of cytoplasmic processes. The development of these changes is depicted, and the dose-response patterns in these cell lines are described. MDBK is generally most resistant and HeLa most sensitive to these effects of CD. Cells in G1 are most sensitive to CD; responsiveness decreases progressively during early S and is least in mid S through G2. CD inhibits transport of [14C]deoxyglucose in HeLa by about 45% but has no significant effect on hexose uptake in Vero and MDBK; sugar transport is thus apparently unrelated to any morphologic effect of CD. Although spreading and attachment are impeded, CD does not decrease and may even enhance the adhesiveness of established monolayers. Contraction appears to be a primary early effect of CD, upon which other visible changes follow. It is prevented by some inhibitors of energy metabolism (deoxyglucose and dinitrophenol) and does not occur in glycerinated models without ATP. The possible bases of the contractile response to CD are discussed. Although direct or indirect action of CD on some microfilaments may occur, a generalized structural disruption of contractile filaments by CD is considered unlikely.

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“…The data suggest that adenylate cyclase cell content and enzyme responsiveness to specific agonists can be independently controlled. In all synchronized cell types so far studied the intracellular 3':5'-cyclic AMP concentration varies at different stages of the cell cycle, being minimal at the time of mitosis and almost always reaching a maximal value in the early GI phase (1)(2)(3)(4).…”

mentioning

confidence: 99%

Adenylate cyclase from synchronized neuroblastoma cells: responsiveness to prostaglandin E1, adenosine, and dopamine during the cell cycle.

Penit¹,

Cantau²,

Huot³

et al. 1977

Proc. Natl. Acad. Sci. U.S.A.

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Neuroblastoma cells were synchronized by a combined isoleucine plus glutamine starvation. Adenylate cyclase activity [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] was measured under basal conditions and in the presence of dopamine, adenosine, and prostaglandin (PG) E1. A clear dissociation occurred between the respective evolution patterns of basal and agonistetimulated adenylate cyclase activities. The magnitudes of the enzyme response to PGE1, adenosine, and dopamine also exhibited different evolution patterns during the cell cycle. Evolution of adenylate cyclase responsiveness to PGE1 during the cell cycle exhibited striking similarities with the intracellular 3':5'-cyclic AMP changes observed elsewhere.Use of theophylline and fluphenazine as specific inhibitors of adenosine and dopamine, respectively, made it possible to demonstrate that adenosine, dopamine, and PGEI stimulated adenylate cyclase through independent receptor sites. Furthermore, whatever the stage of the cell cycle, responses to these three agonists were not additive, indicating that the receptors of adenosine, dopamine, and PGE1 control the same adenylate cyclase moieties. The data suggest that adenylate cyclase cell content and enzyme responsiveness to specific agonists can be independently controlled. In all synchronized cell types so far studied the intracellular 3':5'-cyclic AMP concentration varies at different stages of the cell cycle, being minimal at the time of mitosis and almost always reaching a maximal value in the early GI phase (1-4).More recently it was shown in fibroblasts that at the beginning of the G1 phase intracellular cyclic AMP drops abruptly while 3':5'-cyclic GMP rises. It was suggested that the changes of cyclic nucleotides regulate the cell cycle and more generally that cyclic nucleotides are involved in the "pleiotypic" control of cell growth (5,6 The aim of the present work was to analyze the evolution pattern of adenylate cyclase during the cell cycle in neuroblastoma cells and the evolution patterns of the responses to three different regulatory agents: adenosine, dopamine, and prostaglandin (PG) El. The latter seems to be a candidate for intracellular regulation because several cell lines, including neuroblastoma, are able to synthesize prostaglandins (7). MATERIAL AND METHODSMouse neuroblastoma cells were derived from the cholinergic clone NS20 (8). Current properties of these cells are: total protein content is 0.250 mg/106 cells; specific choline acetyltransferase activity is 60 pmol/mg protein per min. Present karyotype: 80% of the cells have 60 chromosomes and 20% have 120.Cell Culture. Cells were grown on Falcon petri dishes in Eagle's minimal essential medium containing Earle's salts solution supplemented with 10% fetal calf serum (Gibco), penicillin G at 50 international units/ml and streptomycin sulfate at 5 ttg/ml. Cells were incubated at 370 in 90% air/10% CO2.The doubling time of the cell population was close to 20 hr.Synchronization Procedure. Cells were collected during the exponentia...

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Growth Control and Cyclic Alterations of Cyclic AMP in the Cell Cycle

Cited by 238 publications

References 17 publications

A role for cAMP-dependent protein kinase in early embryonic divisions.

A role for cAMP-dependent protein kinase in early embryonic divisions.

Action of Cytochalasin D on Cells of Established Lines

Adenylate cyclase from synchronized neuroblastoma cells: responsiveness to prostaglandin E1, adenosine, and dopamine during the cell cycle.

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