title: Nuclear pores enable sustained perinuclear calcium oscillations.
abstract: Calcium signalling relies on the flux of calcium ions across membranes yet how signals in different compartments are related remains unclear. In particular, similar calcium signals on both sides of the nuclear envelope have been reported and attributed to passive diffusion through nuclear pores. However, observed differing cytosolic and nucleosolic calcium signatures suggest that the signalling machinery in these compartments can act independently.
  
  
  
  We adapt the fire-diffuse-fire model to investigate the generation of perinuclear calcium oscillations. We demonstrate that autonomous spatio-temporal calcium patterns are still possible in the presence of nuclear and cytosolic coupling via nuclear pores. The presence or absence of this autonomy is dependent upon the strength of the coupling and the maximum firing rate of an individual calcium channel. In all cases, coupling through the nuclear pores enables robust signalling with respect to changes in the diffusion constant.
  
  
  
  We show that contradictory interpretations of experimental data with respect to the autonomy of nuclear calcium oscillations can be reconciled within one model, with different observations being a consequence of varying nuclear pore permeabilities for calcium and refractory conditions of channels. Furthermore, our results provide an explanation for why calcium oscillations on both sides of the nuclear envelope may be beneficial for sustained perinuclear signaling.
authors.affiliation: Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK. Teresa.VazMartins@jic.ac.uk.
authors.forename: Teresa Vaz
authors.initials: TV
authors.lastname: Martins
authors.affiliation: Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Evans
authors.affiliation: Mathematics Department, Wenatchee Valley College, Wenatchee, USA.
authors.forename: Derin B
authors.initials: DB
authors.lastname: Wysham
authors.affiliation: Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Morris
mesh_terms: D020013:Calcium Signaling; D004058:Diffusion; D021962:Membrane Microdomains / Q000378:metabolism; D008954:Models, Biological; D009685:Nuclear Envelope / Q000378:metabolism; D022022:Nuclear Pore / Q000378:metabolism*
keywords: Calcium signalling; Fire-diffuse-fire; Nuclear pores