HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 553/3/775    most recent jphysiol.2003.054247v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dargan, S. L. Articles by Parker, I. Search for Related Content PubMed PubMed Citation Articles by Dargan, S. L. Articles by Parker, I.

Buffer kinetics shape the spatiotemporal patterns of IP₃-evoked Ca²⁺ signals

Sheila L. Dargan and Ian Parker

Ca²⁺ liberation through inositol 1,4,5-trisphosphate receptors (IP₃Rs) plays a universal role in cell regulation, and specificity of cell signalling is achieved through the spatiotemporal patterning of Ca²⁺ signals. IP₃Rs display Ca²⁺-induced Ca²⁺ release (CICR), but are grouped in clusters so that regenerative Ca²⁺ signals may remain localized to individual clusters, or propagate globally between clusters by successive cycles of Ca²⁺ diffusion and CICR. We used confocal microscopy and photoreleased IP₃ in Xenopus oocytes to study how these properties are modulated by mobile cytosolic Ca²⁺ buffers. EGTA (a buffer with slow 'on-rate') speeded Ca²⁺ signals and 'balkanized' Ca²⁺ waves by dissociating them into local signals. In contrast, BAPTA (a fast buffer with similar affinity) slowed Ca²⁺ responses and promoted 'globalization' of spatially uniform Ca²⁺ signals. These actions are likely to arise through differential effects on Ca²⁺ feedback within and between IP₃R clusters, because Ca²⁺ signals evoked by influx through voltage-gated channels were little affected. We propose that cell-specific expression of Ca²⁺-binding proteins with distinct kinetics may shape the time course and spatial distribution of IP₃-evoked Ca²⁺ signals for specific physiological roles.

This article has been cited by other articles:

				J. Shuai, J. E. Pearson, and I. Parker Modeling Ca2+ Feedback on a Single Inositol 1,4,5-Trisphosphate Receptor and Its Modulation by Ca2+ Buffers Biophys. J., October 15, 2008; 95(8): 3738 - 3752. [Abstract] [Full Text] [PDF]

				A. Skupin, H. Kettenmann, U. Winkler, M. Wartenberg, H. Sauer, S. C. Tovey, C. W. Taylor, and M. Falcke How Does Intracellular Ca2+ Oscillate: By Chance or by the Clock? Biophys. J., March 15, 2008; 94(6): 2404 - 2411. [Abstract] [Full Text] [PDF]

				J. G. McCarron, S. Chalmers, and T. C. Muir `Quantal' Ca2+ release at the cytoplasmic aspect of the Ins(1,4,5)P3R channel in smooth muscle J. Cell Sci., January 1, 2008; 121(1): 86 - 98. [Abstract] [Full Text] [PDF]

				D. Ragozzino, S. Di Angelantonio, F. Trettel, C. Bertollini, L. Maggi, C. Gross, I. F. Charo, C. Limatola, and F. Eusebi Chemokine Fractalkine/CX3CL1 Negatively Modulates Active Glutamatergic Synapses in Rat Hippocampal Neurons J. Neurosci., October 11, 2006; 26(41): 10488 - 10498. [Abstract] [Full Text] [PDF]

				M. Y. Lee, H. Song, J. Nakai, M. Ohkura, M. I. Kotlikoff, S. P. Kinsey, V. A. Golovina, and M. P. Blaustein Local subplasma membrane Ca2+ signals detected by a tethered Ca2+ sensor PNAS, August 29, 2006; 103(35): 13232 - 13237. [Abstract] [Full Text] [PDF]

				G. Ullah and P. Jung Modeling the Statistics of Elementary Calcium Release Events Biophys. J., May 15, 2006; 90(10): 3485 - 3495. [Abstract] [Full Text] [PDF]

				L. Kreiner and A. Lee Endogenous and Exogenous Ca2+ Buffers Differentially Modulate Ca2+-dependent Inactivation of CaV2.1 Ca2+ Channels J. Biol. Chem., February 24, 2006; 281(8): 4691 - 4698. [Abstract] [Full Text] [PDF]

				H. Salgado, F. Tecuapetla, T. Perez-Rosello, A. Perez-Burgos, E. Perez-Garci, E. Galarraga, and J. Bargas A Reconfiguration of CaV2 Ca2+ Channel Current and Its Dopaminergic D2 Modulation in Developing Neostriatal Neurons J Neurophysiol, December 1, 2005; 94(6): 3771 - 3787. [Abstract] [Full Text] [PDF]