Role of the nuclear envelope in calcium signalling

Abstract

SummaryThe endoplasmic reticulum is the major Ca 2+ store inside the cell. Its organisation in specialised sub-domains allows the local delivery of Ca 2+ to specific cell areas on stimulation. The nuclear envelope, which is continuous with the endoplasmic reticulum, has a double role: it insulates the nucleoplasm from the cytoplasm and it stores Ca 2+ around the nucleus. Furthermore, all the constituents of the signalling cascade leading to Ca 2+ mobilisation are found in the nuclear envelope; this allows the nuclear Ca 2+ to be regulated autonomously. On the other hand, cytosolic Ca 2+ transients can propagate within the nucleus via the nuclear pore complex. The variations in nuclear Ca 2+ concentration are important for controlling gene transcription and for progression in the cell cycle. Recent data suggest that invaginations of the nuclear envelope modify the morphology of the nucleus and may affect Ca 2+ dynamics in the nucleus and regulate transcriptional activity.

Cold Signaling and Cold Response in Plants

“…Nuclear [Ca 2+ ], which is monitored by a chimera protein, formed by the fusion of aequorin to nucleaoplasmin, is also transiently increased after cold shock, and the peak of nuclear [Ca 2+ ] is delayed at 5 to 10 s, compared to the peak of cytosolic [Ca 2+ ] [8]. In animal cells, the increase in nuclear [Ca 2+ ] is caused by nuclear envelope, which is continuous with the endoplasmic reticulum, one of major Ca 2+ stores [9]. The increase in nuclear [Ca 2+ ] can be propagated by cytosolic Ca 2+ transients via the nuclear pore complexes [9].…”

Advances in physiological and molecular aspects of plant cold tolerance

“…Mauger (2012) reported that the increase in nuclear Ca 2+ is caused by a nuclear envelope that is considered one of the major Ca 2+ stores. Moreover, they indicated that the increase in nuclear Ca 2+ can be amplified by cytosolic Ca 2+ transients through the nuclear pore complex.…”

“…Because of the similarity in pore complex system in both animal and plant nuclear membrane (Xu & Meier 2008), it was suggested that the nuclear Ca 2+ signal could be started from the nuclear envelope and propagated by cytosolic Ca 2+ transients in plants as well. However, nuclear Ca 2+ has been reported to have an important role in controlling gene transcription in both plants and animals (Mazars et al 2011;Mauger 2012).…”

Intracellular angiotensin (1–7) increases the inward calcium current in cardiomyocytes. On the role of PKA activation

“…The presence of Ang (1-7) in the nucleus [13] and the role of nuclear envelop on calcium signaling [29] raise the possibility that the heptapeptide present in the nuclear compartment, can be involved in calcium homeostasis. The intracellular dialysis of Ang II caused an effect on I Ca opposite from that elicited by intracellular Ang (1-7) one can conclude that the effect of Ang (1-7) on inward calcium current is unrelated to its conversion to Ang II.…”