Polarized Calcium and Calmodulin Signaling in Secretory Epithelia
Medical Research Council Secretory Control Research Group, The Physiological Laboratory, University of Liverpool, Liverpool, United Kingdom Ashby, Michael C. and Alexei V. Tepikin. Polarized Calcium and Calmodulin Signaling in Secretory Epithelia. Physiol. Rev. 82: 701-734, 2002. This review examine...
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Published in | Physiological reviews Vol. 82; no. 3; pp. 701 - 734 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
United States
Am Physiological Soc
01.07.2002
American Physiological Society |
Subjects | |
Online Access | Get full text |
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Summary: | Medical Research Council Secretory Control Research Group, The
Physiological Laboratory, University of Liverpool, Liverpool,
United Kingdom
Ashby, Michael C. and
Alexei V. Tepikin.
Polarized Calcium and Calmodulin Signaling in Secretory
Epithelia. Physiol. Rev. 82: 701-734, 2002. This review examines
polarized calcium and calmodulin signaling in exocrine epithelial
cells. The calcium ion is a simple, evolutionarily ancient, and
universal second messenger. In exocrine epithelial cells, it
regulates essential functions such as exocytosis, fluid secretion, and
gene expression. Exocrine cells are structurally polarized, with the
apical region usually dedicated to secretion. Recent advances in
technology, in particular the development of videoimaging and confocal
microscopy, have led to the discovery of polarized, subcellular calcium
signals in these cell types. The properties of a rich variety of local
and global calcium signals have now been described in secretory
epithelial cells. Secretagogues stimulate apical-to-basal waves of
calcium in many exocrine cell types, but there are some interesting
exceptions to this rule. The shapes of intracellular calcium signals
are determined by the distribution of calcium-releasing channels
and mechanisms that limit calcium elevation. Polarized distribution of
calcium-handling mechanisms also leads to transcellular calcium
transport in exocrine epithelial cells. This transport can deliver
considerable amounts of calcium into secreted fluids. Multicellular
polarized calcium signals can coordinate the activity of many
individual cells in epithelial secretory tissue. Certain particularly
sensitive cells serve as pacemakers for initiation of intercellular
calcium waves. Many calcium signaling pathways involve activation of
calmodulin. This ubiquitous protein regulates secretion in exocrine
cells and also activates interesting feedback interactions with calcium channels and transporters. Very recently it became possible to directly
study polarized calcium-calmodulin reactions and to visualize the
process of hormone-induced redistribution of calmodulin in live
cells. The structural and functional polarity of secretory epithelia
alongside the polarity of its calcium and calmodulin signaling present
an interesting lesson in tissue organization. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 ObjectType-Review-3 content type line 23 ObjectType-Feature-3 ObjectType-Review-1 |
ISSN: | 0031-9333 1522-1210 |
DOI: | 10.1152/physrev.00006.2002 |