PDF
- Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
201kB |
Item Type: | Article |
---|---|
Title: | Timescales of IP(3)-evoked Ca(2+) spikes emerge from Ca(2+) puffs only at the cellular level |
Creators Name: | Thurley, K., Smith, I.F., Tovey, S.C., Taylor, C.W., Parker, I. and Falcke, M. |
Abstract: | The behavior of biological systems is determined by the properties of their component molecules, but the interactions are usually too complex to understand fully how molecular behavior generates cellular behavior. Ca(2+) signaling by inositol trisphosphate receptors (IP(3)R) offers an opportunity to understand this relationship because the cellular behavior is defined largely by Ca(2+)-mediated interactions between IP(3)R. Ca(2+) released by a cluster of IP(3)R (giving a local Ca(2+) puff) diffuses and ignites the behavior of neighboring clusters (to give repetitive global Ca(2+) spikes). We use total internal reflection fluorescence microscopy of two mammalian cell lines to define the temporal relationships between Ca(2+) puffs (interpuff intervals, IPI) and Ca(2+) spikes (interspike intervals) evoked by flash photolysis of caged IP(3). We find that IPI are much shorter than interspike intervals, that puff activity is stochastic with a recovery time that is much shorter than the refractory period of the cell, and that IPI are not periodic. We conclude that Ca(2+) spikes do not arise from oscillatory dynamics of IP(3)R clusters, but that repetitive Ca(2+) spiking with its longer timescales is an emergent property of the dynamics of the whole cluster array. |
Keywords: | Calcium, Calcium Signaling, Tumor Cell Line, Cells, Fluorescence Microscopy, HEK293 Cells, Inositol 1,4,5-Trisphosphate, Photolysis, Time Factors |
Source: | Biophysical Journal |
ISSN: | 0006-3495 |
Publisher: | Cell Press |
Volume: | 101 |
Number: | 11 |
Page Range: | 2638-2644 |
Date: | 7 December 2011 |
Official Publication: | https://doi.org/10.1016/j.bpj.2011.10.030 |
PubMed: | View item in PubMed |
Repository Staff Only: item control page