Abstract |
Elementary Ca(2+) signals, such as "Ca(2+) puffs", which arise from the activation of inositol 1,4,5-trisphosphate receptors, are building blocks for local and global Ca(2+) signalling. We characterized Ca(2+) puffs in six cell types that expressed differing ratios of the three inositol 1,4,5-trisphosphate receptor isoforms. The amplitudes, spatial spreads and kinetics of the events were similar in each of the cell types. The resemblance of Ca(2+) puffs in these cell types suggests that they are a generic elementary Ca(2+) signal and, furthermore, that the different inositol 1,4,5-trisphosphate isoforms are functionally redundant at the level of subcellular Ca(2+) signalling. Hormonal stimulation of SH-SY5Y neuroblastoma cells and HeLa cells for several hours downregulated inositol 1,4,5-trisphosphate expression and concomitantly altered the properties of the Ca(2+) puffs. The amplitude and duration of Ca(2+) puffs were substantially reduced. In addition, the number of Ca(2+) puff sites active during the onset of a Ca(2+) wave declined. The consequence of the changes in Ca(2+) puff properties was that cells displayed a lower propensity to trigger regenerative Ca(2+) waves. Therefore, Ca(2+) puffs underlie inositol 1,4,5-trisphosphate signalling in diverse cell types and are focal points for regulation of cellular responses.
|
Authors | S C Tovey, P de Smet, P Lipp, D Thomas, K W Young, L Missiaen, H De Smedt, J B Parys, M J Berridge, J Thuring, A Holmes, M D Bootman |
Journal | Journal of cell science
(J Cell Sci)
Vol. 114
Issue Pt 22
Pg. 3979-89
(Nov 2001)
ISSN: 0021-9533 [Print] England |
PMID | 11739630
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Calcium Channels
- ITPR1 protein, human
- Inositol 1,4,5-Trisphosphate Receptors
- Protein Isoforms
- Receptors, Cytoplasmic and Nuclear
- Histamine
- Inositol 1,4,5-Trisphosphate
- Adenosine Triphosphate
- Carbachol
- Calcium
|
Topics |
- Adenosine Triphosphate
(pharmacology)
- Animals
- Calcium
(metabolism)
- Calcium Channels
(genetics, metabolism)
- Calcium Signaling
(drug effects, physiology)
- Carbachol
(pharmacology)
- Cell Line
- Cell Nucleus
(metabolism)
- Down-Regulation
- Histamine
(pharmacology)
- Humans
- Immunohistochemistry
- Inositol 1,4,5-Trisphosphate
(metabolism)
- Inositol 1,4,5-Trisphosphate Receptors
- Protein Isoforms
(genetics, metabolism)
- Receptors, Cytoplasmic and Nuclear
(genetics, metabolism)
|