CRAC channels in secretory epithelial cell function and disease
Haiping Liu1, Ahmed Kabrah1, Malini Ahuja1
1Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, United States.
Cell Calcium
|January 15, 2019
Summary
Calcium (Ca2+) signaling in secretory cells is vital for cell functions like exocytosis and fluid secretion. This review explores Ca2+ influx channels and lipid roles at ER/PM junctions, crucial for cellular processes and disease.
Area of Science:
- Cellular Biology
- Physiology
- Biochemistry
Background:
- Receptor-evoked calcium (Ca2+) signals are essential for secretory epithelia functions, including exocytosis and fluid secretion.
- Calcium influx, mediated by TRPC and STIM1-activated Orai1 channels (CRAC), is a critical component of these signals.
- These Ca2+ signals are generated at ER/PM junctions, sites of material exchange vital for cellular processes.
Purpose of the Study:
- To review the general properties of Ca2+ signaling at ER/PM junctions in secretory cells.
- To discuss the role of phosphoinositides, such as PI(4,5)P2, and other lipids in regulating Ca2+ signaling.
- To explore the implications of uncontrolled Ca2+ influx in secretory cell function and disease.
Main Methods:
- Literature review of studies on calcium signaling in secretory epithelia.
- Analysis of the roles of TRPC and Orai1 channels in calcium influx.
- Examination of lipid involvement at ER/PM junctions.
Main Results:
- Calcium influx through TRPC and Orai1 channels is central to receptor-evoked Ca2+ signals.
- ER/PM junctions are critical sites for Ca2+ signal generation and regulation.
- Specific lipids, including PI(4,5)P2, influence Ca2+ channel activity and cellular function.
Conclusions:
- Proper regulation of Ca2+ signaling at ER/PM junctions is crucial for secretory cell function.
- Dysregulation of Ca2+ influx can lead to diseases associated with secretory epithelia.
- Understanding these mechanisms provides insights into potential therapeutic targets.
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