Using two dyes to observe the competition of Ca 2+ trapping mechanisms and their effect on intracellular Ca 2+ signals
The specificity and universality of intracellular Ca 2+ signals rely on the variety of spatio-temporal patterns that the Ca 2+ concentration can display. Ca 2+ liberation through inositol 1,4,5-trisphosphate receptors (IP 3 Rs) is key for this variety. In this paper, we study how the competition bet...
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2018
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14783967_v15_n6_p_Piegari http://hdl.handle.net/20.500.12110/paper_14783967_v15_n6_p_Piegari |
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paper:paper_14783967_v15_n6_p_Piegari2023-06-08T16:18:21Z Using two dyes to observe the competition of Ca 2+ trapping mechanisms and their effect on intracellular Ca 2+ signals calcium buffers calcium puffs spatio-temporal distributions aniline derivative coloring agent Fluo 4 fused heterocyclic rings rhod-2 xanthene derivative animal calcium signaling chemistry kinetics oocyte physiology Xenopus laevis Aniline Compounds Animals Calcium Signaling Coloring Agents Heterocyclic Compounds, 3-Ring Kinetics Oocytes Xanthenes Xenopus laevis The specificity and universality of intracellular Ca 2+ signals rely on the variety of spatio-temporal patterns that the Ca 2+ concentration can display. Ca 2+ liberation through inositol 1,4,5-trisphosphate receptors (IP 3 Rs) is key for this variety. In this paper, we study how the competition between buffers of different kinetics affects Ca 2+ signals that involve Ca 2+ release through IP 3 Rs. The study also provides insight into the underlying spatial distribution of the channels that participate in the signals. Previous works on the effects of Ca 2+ buffers have drawn conclusions 'indirectly' by observing the Ca 2+ -bound dye distributions in the presence of varying concentrations of exogenous buffers and using simulations to interpret the results. In this paper, we make visible the invisible by observing the signals simultaneously with two dyes, Rhod-2 and Fluo-4, each of which plays the role of a slow or fast Ca 2+ buffer, respectively. Our observations obtained for different concentrations of Fluo-4 highlight the dual role that fast buffers exert on the dynamics, either reducing the intracluster channel coupling or preventing channel inhibition and allowing the occurrence of relatively long cycles of Ca 2+ release. Our experiments also show that signals with relatively high Ca 2+ release rates remain localized in the presence of large Rhod-2 concentrations, while the mean speed of the elicited waves increases. We interpret this as a consequence of the more effective uncoupling between IP 3 R clusters as the slow dye concentration increases. Combining the analysis of the experiments with numerical simulations, we also conclude that Ca 2+ release not only occurs within the close vicinity of the centers of the clearly identifiable release sites (IP 3 R clusters) but there are also functional IP 3 Rs in between them. © 2018 IOP Publishing Ltd. 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14783967_v15_n6_p_Piegari http://hdl.handle.net/20.500.12110/paper_14783967_v15_n6_p_Piegari |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
calcium buffers calcium puffs spatio-temporal distributions aniline derivative coloring agent Fluo 4 fused heterocyclic rings rhod-2 xanthene derivative animal calcium signaling chemistry kinetics oocyte physiology Xenopus laevis Aniline Compounds Animals Calcium Signaling Coloring Agents Heterocyclic Compounds, 3-Ring Kinetics Oocytes Xanthenes Xenopus laevis |
| spellingShingle |
calcium buffers calcium puffs spatio-temporal distributions aniline derivative coloring agent Fluo 4 fused heterocyclic rings rhod-2 xanthene derivative animal calcium signaling chemistry kinetics oocyte physiology Xenopus laevis Aniline Compounds Animals Calcium Signaling Coloring Agents Heterocyclic Compounds, 3-Ring Kinetics Oocytes Xanthenes Xenopus laevis Using two dyes to observe the competition of Ca 2+ trapping mechanisms and their effect on intracellular Ca 2+ signals |
| topic_facet |
calcium buffers calcium puffs spatio-temporal distributions aniline derivative coloring agent Fluo 4 fused heterocyclic rings rhod-2 xanthene derivative animal calcium signaling chemistry kinetics oocyte physiology Xenopus laevis Aniline Compounds Animals Calcium Signaling Coloring Agents Heterocyclic Compounds, 3-Ring Kinetics Oocytes Xanthenes Xenopus laevis |
| description |
The specificity and universality of intracellular Ca 2+ signals rely on the variety of spatio-temporal patterns that the Ca 2+ concentration can display. Ca 2+ liberation through inositol 1,4,5-trisphosphate receptors (IP 3 Rs) is key for this variety. In this paper, we study how the competition between buffers of different kinetics affects Ca 2+ signals that involve Ca 2+ release through IP 3 Rs. The study also provides insight into the underlying spatial distribution of the channels that participate in the signals. Previous works on the effects of Ca 2+ buffers have drawn conclusions 'indirectly' by observing the Ca 2+ -bound dye distributions in the presence of varying concentrations of exogenous buffers and using simulations to interpret the results. In this paper, we make visible the invisible by observing the signals simultaneously with two dyes, Rhod-2 and Fluo-4, each of which plays the role of a slow or fast Ca 2+ buffer, respectively. Our observations obtained for different concentrations of Fluo-4 highlight the dual role that fast buffers exert on the dynamics, either reducing the intracluster channel coupling or preventing channel inhibition and allowing the occurrence of relatively long cycles of Ca 2+ release. Our experiments also show that signals with relatively high Ca 2+ release rates remain localized in the presence of large Rhod-2 concentrations, while the mean speed of the elicited waves increases. We interpret this as a consequence of the more effective uncoupling between IP 3 R clusters as the slow dye concentration increases. Combining the analysis of the experiments with numerical simulations, we also conclude that Ca 2+ release not only occurs within the close vicinity of the centers of the clearly identifiable release sites (IP 3 R clusters) but there are also functional IP 3 Rs in between them. © 2018 IOP Publishing Ltd. |
| title |
Using two dyes to observe the competition of Ca 2+ trapping mechanisms and their effect on intracellular Ca 2+ signals |
| title_short |
Using two dyes to observe the competition of Ca 2+ trapping mechanisms and their effect on intracellular Ca 2+ signals |
| title_full |
Using two dyes to observe the competition of Ca 2+ trapping mechanisms and their effect on intracellular Ca 2+ signals |
| title_fullStr |
Using two dyes to observe the competition of Ca 2+ trapping mechanisms and their effect on intracellular Ca 2+ signals |
| title_full_unstemmed |
Using two dyes to observe the competition of Ca 2+ trapping mechanisms and their effect on intracellular Ca 2+ signals |
| title_sort |
using two dyes to observe the competition of ca 2+ trapping mechanisms and their effect on intracellular ca 2+ signals |
| publishDate |
2018 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14783967_v15_n6_p_Piegari http://hdl.handle.net/20.500.12110/paper_14783967_v15_n6_p_Piegari |
| _version_ |
1768544055167287296 |