ID 111475
Author
Tanimura, Akihiko Health Sciences University of Hokkaido
Morita, Takao Health Sciences University of Hokkaido
Nezu, Akihiro Health Sciences University of Hokkaido
Tojyo, Yosuke Health Sciences University of Hokkaido
Keywords
inositol 1,4,5-trisphosphate
calcium
FRET
biosensor
Content Type
Journal Article
Description
Inositol 1,4,5-trisphosphate (IP3) is an intracellular messenger that elicits a wide range of spatial and temporal Ca2+ signals, and this signaling versatility is exploited to regulate diverse cellular responses. In the present study, we have developed a series of IP3 biosensors that exhibit strong pH stability and varying affinities for IP3, as well as a method for the quantitative measurement of cytosolic concentrations of IP3 ([IP3]i) in single living cells. We applied this method to elucidate IP3 dynamics during agonist-induced Ca2+ oscillations, and demonstrated cell type-dependent differences in IP3 dynamics ; a non-fluctuating rise in [IP3]i and repetitive IP3 spikes during Ca2+ oscillations in COS-7 cells and HSY-EA1 cells, respectively. The size of the IP3 spikes in HSY-EA1 cells varied from 10 to 100 nM, and the [IP3]i spike peak was preceded by a Ca2+ spike peak. These results suggest that repetitive IP3 spikes in HSY-EA1 cells are passive reflections of Ca2+ oscillations, and are unlikely to be essential for driving Ca2+ oscillations. The novel method described herein as well as the quantitative information obtained by using this method should provide a valuable and sound basis for future studies on the spatial and temporal regulations of IP3 and Ca2+.
Journal Title
The Journal of Medical Investigation
ISSN
13496867
13431420
NCID
AA11166929
AA12022913
Publisher
Faculty of Medicine Tokushima University
Volume
56
Issue
Supplement
Start Page
357
End Page
361
Sort Key
357
Published Date
2009-12
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Publisher