Bcl-2 and Ca2+ homeostasis in the endoplasmic reticulum
1Department of Experimental and Diagnostic Medicine, Section of General Pathology, ER-GenTech laboratory and Interdisciplinary Center for the Study of Inflammation (ICSI), University of Ferrara, Italy.
Cell Death and Differentiation
|May 27, 2006
Summary
Bcl-2 protein influences calcium ion (Ca2+) levels in the endoplasmic reticulum (ER), affecting cell signaling and apoptosis sensitivity. This review explores Bcl-2
Area of Science:
- Cell Biology
- Molecular Biology
- Calcium Signaling
Background:
- Emerging evidence indicates Bcl-2 protein impacts intracellular calcium ion (Ca2+) homeostasis.
- Bcl-2 influences both basal Ca2+ levels and Ca2+ flux in response to stimuli.
- Altered Ca2+ signaling is implicated in regulating cell survival and apoptosis.
Purpose of the Study:
- To review the effects of Bcl-2 on endoplasmic reticulum (ER) Ca2+ concentration ([Ca2+]er).
- To discuss the functional significance of Bcl-2-mediated Ca2+ signaling alterations.
- To examine the underlying mechanisms by which Bcl-2 modulates Ca2+ signaling.
Main Methods:
- Direct measurement of ER Ca2+ concentration using recombinant probes in Bcl-2-overexpressing cells.
- Indirect assessment of Ca2+ content in intracellular pools using cytosolic probes.
- Review of existing literature on Bcl-2, Ca2+ signaling, and apoptosis.
Main Results:
- Bcl-2 overexpression leads to reduced ER Ca2+ filling and increased Ca2+ leak from the ER.
- Cytosolic Ca2+ measurements show a more complex picture, with no consistent changes in intracellular pool Ca2+ content.
- Ca2+ signals are critical for apoptotic checkpoints, including mitochondrial function, influencing cellular responses.
Conclusions:
- Bcl-2 plays a significant role in regulating ER Ca2+ homeostasis.
- Modulation of Ca2+ signaling by Bcl-2 impacts cellular sensitivity to apoptotic stimuli.
- Further research is needed to fully elucidate the mechanisms of Bcl-2's action on Ca2+ signaling.
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