CYCLIC AMP AND OTHER SIGNALS CONTROLLING CELL DEVELOPMENT AND DIFFERENTIATION IN <i>DICTYOSTELIUM</i>

“…3B). Treating cells with cAMP pulses, which are known to stimulate expres- sion of some developmental genes and to repress a class of growth phase genes [18], did not affect the expression of vatB (data not shown).…”

Section: Temporal Regulation Of Vatbmentioning

confidence: 91%

Cloning and transcriptional regulation of the gene encoding the vacuolar/H⁺ ATPase B subunit of Dictyostelium discoideum

et al. 1997

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“…After starvation, these cells stop growing and dividing, and embark on a developmental program that includes their aggregation by chemotaxis toward signals of cAMP emitted by cells behaving as aggregation centers, and the subsequent transformation of this multicellular aggregate, which can contain up to 10 5 cells, into a fruiting body surmounted by a mass of spores. The life cycle resumes after the spores have been dispersed in the environment [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

Modeling oscillations and waves of cAMP in Dictyostelium discoideum cells

Halloy

Lauzeral

Goldbeter

1998

Biophysical Chemistry

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We examine the theoretical aspects of temporal and spatiotemporal organization in the cAMP signaling system of Dictyostelium discoideum amoebae which aggregate in a wavelike manner after starvation, in response to pulses of cAMP emitted with a periodicity of several minutes by cells behaving as aggregation centers. We first extend the model based on receptor desensitization, previously proposed by Martiel and Goldbeter, by incorporating the role of G proteins in signal transduction. The extended model accounts for observations on the response of the signaling system to successive step increases in extracellular cAMP. In the presence of the positive feedback loop in cAMP synthesis, this model generates sustained oscillations in cAMP and in the fraction of active cAMP receptor, similar to those obtained in the simpler model where the role of the G proteins is not taken into account explicitly. We use the latter model to address the formation of concentric and spiral waves of cAMP in the course of D. discoideum aggregation. Previous analyses of the model showed that a progressive increase in the activity of adenylate cyclase and phosphodiesterase can account for the transitions no relayrelay-oscillations-relay observed in the experiments. We show that the degree of cellular synchronization on such a developmental path in parameter space markedly affects the nature of the spatial patterns generated by the model. These patterns range from concentric waves to a small number of large spirals, and finally to a large number of smaller spirals, as the degree of developmental desynchronization between cells increases.

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“…After several minutes of continuous occupancy, the receptor is fully phosphorylated and the cells no longer respond to CAMP although the receptor is still capable of binding CAMP In vivo, adaptation is reversed by diffusion and hydrolysis of CAMP by developmentally regulated cell surface and secreted forms of phosphodiesterase (PDE; Gerisch, 1987;Kessin, 1988). Removal of CAMP induces a gradual loss of receptor phosphorylation and a return of the cells to a basal, sensitized state.…”

Section: Events At the Membranementioning

confidence: 99%

“…A number of pulse-induced genes encode proteins with functions that are required for aggregation, such as the CAMP receptor itself, G,2, contact sites A (a cell adhesion molecule), and gene 02, a serine esterase required for aggregation, as determined by blocking its expression with antisense RNA (Gerisch, 1987;Kimmel, 1987;Klein et al, 1988;Kumagai et al, 1989;Mann et al, 1988). About 100 genes not required for growth are required for aggregation.…”

Section: Regulation Of Early Gene Expression By Campmentioning

confidence: 99%

G protein linked signal transduction pathways in development: Dictyostelium as an experimental system

Firtel

Haastert

Kimmel

et al. 1989

Cell

140

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CYCLIC AMP AND OTHER SIGNALS CONTROLLING CELL DEVELOPMENT AND DIFFERENTIATION IN DICTYOSTELIUM

Cited by 234 publications

References 73 publications

Cloning and transcriptional regulation of the gene encoding the vacuolar/H⁺ ATPase B subunit of Dictyostelium discoideum

Cloning and transcriptional regulation of the gene encoding the vacuolar/H⁺ ATPase B subunit of Dictyostelium discoideum

Modeling oscillations and waves of cAMP in Dictyostelium discoideum cells

G protein linked signal transduction pathways in development: Dictyostelium as an experimental system

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CYCLIC AMP AND OTHER SIGNALS CONTROLLING CELL DEVELOPMENT AND DIFFERENTIATION IN DICTYOSTELIUM

Cited by 234 publications

References 73 publications

Cloning and transcriptional regulation of the gene encoding the vacuolar/H+ ATPase B subunit of Dictyostelium discoideum

Cloning and transcriptional regulation of the gene encoding the vacuolar/H+ ATPase B subunit of Dictyostelium discoideum

Modeling oscillations and waves of cAMP in Dictyostelium discoideum cells

G protein linked signal transduction pathways in development: Dictyostelium as an experimental system

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Product

Resources

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Cloning and transcriptional regulation of the gene encoding the vacuolar/H⁺ ATPase B subunit of Dictyostelium discoideum

Cloning and transcriptional regulation of the gene encoding the vacuolar/H⁺ ATPase B subunit of Dictyostelium discoideum