Medical College of Wisconsin
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Role of elementary Ca(2+) puffs in generating repetitive Ca(2+) oscillations. EMBO J 2001 Jan 15;20(1-2):65-76 PMID: 11226156 PMCID: PMC140189

Abstract

Inositol (1,4,5)-trisphosphate (IP(3)) liberates intracellular Ca(2+) both as localized 'puffs' and as repetitive waves that encode information in a frequency-dependent manner. Using video-rate confocal imaging, together with photorelease of IP(3) in Xenopus oocytes, we investigated the roles of puffs in determining the periodicity of global Ca(2+) waves. Wave frequency is not delimited solely by cyclical recovery of the cell's ability to support wave propagation, but further involves sensitization of Ca(2+)-induced Ca(2+) release by progressive increases in puff frequency and amplitude at numerous sites during the interwave period, and accumulation of pacemaker Ca(2+), allowing a puff at a 'focal' site to trigger a subsequent wave. These specific 'focal' sites, distinguished by their higher sensitivity to IP(3) and close apposition to neighboring puff sites, preferentially entrain both the temporal frequency and spatial directionality of Ca(2+) waves. Although summation of activity from many stochastic puff sites promotes the generation of regularly periodic global Ca(2+) signals, the properties of individual Ca(2+) puffs control the kinetics of Ca(2+) spiking and the (higher) frequency of subcellular spikes in their local microdomain.

Author List

Marchant JS, Parker I

Author

Jonathan S. Marchant PhD Chair, Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Calcium
Calcium Signaling
Cytoplasmic Granules
Egtazic Acid
Female
Kinetics
Microscopy, Confocal
Oocytes
Oscillometry
Xenopus laevis



View this publication's entry at the Pubmed website PMID: 11226156
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