Views

  • State: Published

Activation of the Liver Glycogen Phosphorylase by Ca2+ Oscillations: a Theoretical Study

Exposure Information

Latest Related Exposure To the presentational view for the most recent revision of data reviewed and published from the workspace related to this one.

Workspace Summary

Description
Cytosolic calcium plays a crucial role as a second messenger in cellular signalling. Various cell types, including hepatocytes, display Ca2+ oscillations when stimulated by an extracellular signal. However, the biological relevance of this temporal organization remains unclear. In this paper, we investigate theoretically the e!ect of Ca2+ oscillations on a particular example of cell regulation: the phosphorylation/dephosphorylation cycle controlling the activation of glycogen phosphorylase in hepatocytes. By modelling periodic sinusoidal variations in the intracellular Ca2+ concentration, we show that Ca2+ oscillations reduce the threshold for the activation of the enzyme. Furthermore, as the activation of a given enzyme depends on the kinetics of its phosphorylation/dephosphorylation cycle, speciality can be encoded by the oscillation frequency. Finally, using a model for signal-induced Ca2+ oscillations based on Ca2+-induced Ca2+ release, we show that realistic Ca2+ oscillations can potentiate the response to a hormonal stimulation. These results indicate that Ca2+ oscillations in hepatocytes could contribute to increase the efficiency and speciality of cellular signalling, as shown experimentally for gene expression in lymphocytes (Dolmetsch et al., 1998).
Owner
Mathieu Deneux <mathieu.deneux@gmail.com>
URI for git clone/pull/push
https://models.fieldml.org/workspace/35d
Report an issue with this workspace

Files

Filename Size Date Options
.DS_Store 6148 2016-07-28 [browse]
gall_2000.ai 1138416 2016-07-28 [browse]
gall_2000.cellml 16758 2016-07-28 [browse]
gall_2000.html 2468 2016-07-28 [browse]
gall_2000.png 47194 2016-07-28 [browse]
gall_2000.session.xml 11026 2016-07-28 [browse] [run]
gall_2000.svg 191283 2016-07-28 [browse]
gall_2000.xul 198151 2016-07-28 [browse]
gall_2000_Fig2a.sedml 3193 2016-07-28 [browse]
gall_2000_Fig5.sedml 4156 2016-07-28 [browse]
gall_2000_take2.cellml 10253 2016-07-28 [browse]
gall_2000b.cellml 25784 2016-07-28 [browse]
gall_2000b.session.xml 12282 2016-07-28 [browse] [run]