A dual role for Ca(2+) in autophagy regulation
Jean-Paul Decuypere1, Geert Bultynck, Jan B Parys
1Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg O/N-1 bus 802, Herestraat 49, BE-3000 Leuven, Belgium.
Cell Calcium
|May 17, 2011
Summary
Intracellular calcium (Ca2+) signaling can either suppress or promote autophagy, a key cellular process. This overview explores conflicting evidence and proposes a model for how Ca2+ signaling impacts autophagy based on cellular conditions.
Area of Science:
- Cellular Biology
- Molecular Biology
- Biochemistry
Background:
- Autophagy is a fundamental cellular process for maintaining homeostasis and survival under stress.
- Intracellular calcium (Ca2+) is recognized as a critical regulator of autophagy.
- Conflicting evidence exists regarding the precise role of Ca2+ signaling in modulating autophagy.
Purpose of the Study:
- To critically review the existing literature on the dual role of intracellular Ca2+ in regulating autophagy.
- To discuss the opposing hypotheses concerning Ca2+ signaling and autophagy.
- To propose a model that reconciles the divergent effects of Ca2+ on autophagy.
Main Methods:
- Literature review and critical analysis of published studies.
- Discussion of experimental evidence supporting different roles of Ca2+.
- Synthesis of data to formulate a unifying model.
Main Results:
- Evidence suggests that inositol 1,4,5-trisphosphate receptors (IP3Rs) mediate Ca2+ signals that suppress autophagy.
- Conversely, elevated cytosolic Ca2+ concentrations ([Ca2+]cyt) have been shown to promote autophagic activity.
- The outcome of Ca2+ signaling on autophagy appears context-dependent.
Conclusions:
- Intracellular Ca2+ signaling exerts complex and often opposing effects on autophagy.
- The cellular state and specific Ca2+ signaling pathways dictate whether autophagy is suppressed or promoted.
- A unified model is proposed to explain the dual role of Ca2+ in autophagy regulation.
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