RT info:eu-repo/semantics/article
T1 The coupling of plasma membrane calcium entry to calcium uptake by endoplasmic reticulum and mitochondria
A1 García-Sancho Martín, Francisco Javier
K1 Calcio - Absorción
AB Cross-talk between organelles and plasma membrane Ca2+ channels is essential formodulation of the cytosolic Ca2+ ([Ca2+]C) signals, but such modulation may differ amongcells. In chromaffin cells Ca2+ entry through voltage-operated channels induces calcium releasefrom the endoplasmic reticulum (ER) that amplifies the signal. [Ca2+]C microdomains as highas 20–50 μM are sensed by subplasmalemmal mitochondria, which accumulate large amounts ofCa2+ through the mitochondrial Ca2+ uniporter (MCU). Mitochondria confine the high-Ca2+microdomains (HCMDs) to beneath the plasma membrane,where exocytosis of secretory vesicleshappens. Cell core [Ca2+]C is much smaller (1–2 μM). By acting as a Ca2+ sink, mitochondriastabilise theHCMDin space and time. In non-excitableHEK293 cells, activation of store-operatedCa2+ entry, triggered by ERCa2+ emptying, also generated subplasmalemmal HCMDs, but, in thiscase, most of the Ca2+ was taken up by the ER rather than bymitochondria. The smaller size of the[Ca2+]C peak in this case (about 2 μM)may contribute to this outcome, as the sarco-endoplasmicreticulum Ca2+ ATPase has much higher Ca2+ affinity than MCU. It is also possible that the relative positioning of organelles, channels and effectors, as well as cytoskeleton and accessoryproteins plays an important role.
PB The Physiological Society
SN 0022-3751
YR 2014
FD 2014
LK http://uvadoc.uva.es/handle/10324/6348
UL http://uvadoc.uva.es/handle/10324/6348
LA eng
NO Journal of Physiology, 2014, p. 261-268
NO Producción Científica
DS UVaDOC
RD 20-abr-2024